MediaSession2: Tell framework about new MediaSession2

Bug: 122234817
Test: Build and flash manually.
Change-Id: If210762c51d33e72ea09e6328eea435b68d2eaa4

media/java/android/media/MediaSession2.java

@@ -464,7 +464,21 @@ public class MediaSession2 implements AutoCloseable {
             if (mId == null) {
                 mId = "";
             }
-            return new MediaSession2(mContext, mId, mSessionActivity, mCallbackExecutor, mCallback);
+            MediaSession2 session2 = new MediaSession2(mContext, mId, mSessionActivity,
+                    mCallbackExecutor, mCallback);
+
+            // Notify framework about the newly create session after the constructor is finished.
+            // Otherwise, framework may access the session before the initialization is finished.
+            try {
+                MediaSessionManager manager = (MediaSessionManager) mContext.getSystemService(
+                        Context.MEDIA_SESSION_SERVICE);
+                manager.notifySession2Created(session2.getSessionToken());
+            } catch (Exception e) {
+                session2.close();
+                throw e;
+            }
+
+            return session2;
         }
     }
 

media/java/android/media/Session2Token.aidl

+/*
+ * Copyright 2019 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.media;
+
+parcelable Session2Token;

media/java/android/media/Session2Token.java

@@ -102,7 +102,8 @@ public final class Session2Token implements Parcelable {
     private final ComponentName mComponentName;
 
     /**
-     * Constructor for the token.
+     * Constructor for the token with type {@link #TYPE_SESSION_SERVICE} or
+     * {@link #TYPE_LIBRARY_SERVICE}.
      *
      * @param context The context.
      * @param serviceComponent The component name of the service.
@@ -119,7 +120,7 @@ public final class Session2Token implements Parcelable {
         final int uid = getUid(manager, serviceComponent.getPackageName());
 
         // TODO: Uncomment below to stop hardcode type.
-        final int type = TYPE_SESSION;
+        final int type = TYPE_SESSION_SERVICE;
 //        final int type;
 //        if (isInterfaceDeclared(manager, MediaLibraryService2.SERVICE_INTERFACE,
 //                serviceComponent)) {

media/java/android/media/session/ISessionManager.aidl

@@ -17,6 +17,7 @@ package android.media.session;
 
 import android.content.ComponentName;
 import android.media.IRemoteVolumeController;
+import android.media.Session2Token;
 import android.media.session.IActiveSessionsListener;
 import android.media.session.ICallback;
 import android.media.session.IOnMediaKeyListener;
@@ -32,6 +33,7 @@ import android.view.KeyEvent;
  */
 interface ISessionManager {
     ISession createSession(String packageName, in ISessionCallback cb, String tag, int userId);
+    void notifySession2Created(in Session2Token sessionToken);
     List<IBinder> getSessions(in ComponentName compName, int userId);
     void dispatchMediaKeyEvent(String packageName, boolean asSystemService, in KeyEvent keyEvent,
             boolean needWakeLock);

media/java/android/media/session/MediaSessionManager.java

@@ -26,6 +26,8 @@ import android.content.ComponentName;
 import android.content.Context;
 import android.media.AudioManager;
 import android.media.IRemoteVolumeController;
+import android.media.MediaSession2;
+import android.media.Session2Token;
 import android.media.browse.MediaBrowser;
 import android.os.Handler;
 import android.os.IBinder;
@@ -101,6 +103,30 @@ public final class MediaSessionManager {
         return mService.createSession(mContext.getPackageName(), cbStub, tag, userId);
     }
 
+    /**
+     * Notifies that a new {@link MediaSession2} with type {@link Session2Token#TYPE_SESSION} is
+     * created.
+     * <p>
+     * Do not use this API directly, but create a new instance through the
+     * {@link MediaSession2.Builder} instead.
+     *
+     * @param token newly created session2 token
+     * @hide
+     */
+    public void notifySession2Created(@NonNull Session2Token token) {
+        if (token == null) {
+            throw new IllegalArgumentException("token shouldn't be null");
+        }
+        if (token.getType() != Session2Token.TYPE_SESSION) {
+            throw new IllegalArgumentException("token's type should be TYPE_SESSION");
+        }
+        try {
+            mService.notifySession2Created(token);
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+        }
+    }
+
     /**
      * Get a list of controllers for all ongoing sessions. The controllers will
      * be provided in priority order with the most important controller at index

services/core/java/com/android/server/media/MediaSessionService.java

@@ -40,6 +40,7 @@ import android.media.AudioPlaybackConfiguration;
 import android.media.AudioSystem;
 import android.media.IAudioService;
 import android.media.IRemoteVolumeController;
+import android.media.Session2Token;
 import android.media.session.IActiveSessionsListener;
 import android.media.session.ICallback;
 import android.media.session.IOnMediaKeyListener;
@@ -894,6 +895,21 @@ public class MediaSessionService extends SystemService implements Monitor {
             }
         }
 
+        @Override
+        public void notifySession2Created(Session2Token sessionToken) throws RemoteException {
+            final int pid = Binder.getCallingPid();
+            final int uid = Binder.getCallingUid();
+            final long token = Binder.clearCallingIdentity();
+            try {
+                if (DEBUG) {
+                    Log.d(TAG, "Session2 is created " + sessionToken);
+                }
+                // TODO: Keep the session.
+            } finally {
+                Binder.restoreCallingIdentity(token);
+            }
+        }
+
         @Override
         public List<IBinder> getSessions(ComponentName componentName, int userId) {
             final int pid = Binder.getCallingPid();