Jaewan Kim | ceb6b6e | 2018-01-21 20:56:10 +0900 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2018 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.server.media; |
| 18 | |
| 19 | import android.annotation.CallSuper; |
| 20 | import android.annotation.NonNull; |
| 21 | import android.annotation.Nullable; |
| 22 | import android.content.Context; |
| 23 | import android.media.IMediaSession2; |
| 24 | import android.media.MediaController2; |
| 25 | import android.media.MediaSession2; |
| 26 | import android.media.SessionToken; |
| 27 | import android.os.Handler; |
| 28 | import android.os.Looper; |
| 29 | import android.util.Log; |
| 30 | import java.util.concurrent.Executor; |
| 31 | import java.util.concurrent.atomic.AtomicBoolean; |
| 32 | |
| 33 | /** |
| 34 | * Records a {@link MediaSession2} and holds {@link MediaController2}. |
| 35 | * <p> |
| 36 | * Owner of this object should handle synchronization. |
| 37 | */ |
| 38 | class MediaSession2Record { |
| 39 | interface SessionDestroyedListener { |
| 40 | void onSessionDestroyed(MediaSession2Record record); |
| 41 | } |
| 42 | |
| 43 | private static final String TAG = "Session2Record"; |
| 44 | private static final boolean DEBUG = true; // TODO(jaewan): Change |
| 45 | |
| 46 | private final Context mContext; |
| 47 | private final SessionDestroyedListener mSessionDestroyedListener; |
| 48 | |
| 49 | // TODO(jaewan): Replace these with the mContext.getMainExecutor() |
| 50 | private final Handler mMainHandler; |
| 51 | private final Executor mMainExecutor; |
| 52 | |
| 53 | private MediaController2 mController; |
| 54 | private ControllerCallback mControllerCallback; |
| 55 | |
| 56 | private int mSessionPid; |
| 57 | |
| 58 | /** |
| 59 | * Constructor |
| 60 | */ |
| 61 | public MediaSession2Record(@NonNull Context context, |
| 62 | @NonNull SessionDestroyedListener listener) { |
| 63 | mContext = context; |
| 64 | mSessionDestroyedListener = listener; |
| 65 | |
| 66 | mMainHandler = new Handler(Looper.getMainLooper()); |
| 67 | mMainExecutor = (runnable) -> { |
| 68 | mMainHandler.post(runnable); |
| 69 | }; |
| 70 | } |
| 71 | |
| 72 | public int getSessionPid() { |
| 73 | return mSessionPid; |
| 74 | } |
| 75 | |
| 76 | public Context getContext() { |
| 77 | return mContext; |
| 78 | } |
| 79 | |
| 80 | @CallSuper |
| 81 | public void onSessionDestroyed() { |
| 82 | if (mController != null) { |
| 83 | mControllerCallback.destroy(); |
Jaewan Kim | cf707c4 | 2018-01-24 13:13:53 +0900 | [diff] [blame] | 84 | mController.close(); |
Jaewan Kim | ceb6b6e | 2018-01-21 20:56:10 +0900 | [diff] [blame] | 85 | mController = null; |
| 86 | } |
| 87 | mSessionPid = 0; |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Create session token and tell server that session is now active. |
| 92 | * |
| 93 | * @param sessionPid session's pid |
| 94 | * @return a token if successfully set, {@code null} if sanity check fails. |
| 95 | */ |
| 96 | // TODO(jaewan): also add uid for multiuser support |
| 97 | @CallSuper |
| 98 | public @Nullable |
| 99 | SessionToken createSessionToken(int sessionPid, String packageName, String id, |
| 100 | IMediaSession2 sessionBinder) { |
| 101 | if (mController != null) { |
| 102 | if (mSessionPid != sessionPid) { |
| 103 | // A package uses the same id for session across the different process. |
| 104 | return null; |
| 105 | } |
| 106 | // If a session becomes inactive and then active again very quickly, previous 'inactive' |
| 107 | // may not have delivered yet. Check if it's the case and destroy controller before |
| 108 | // creating its session record to prevents getXXTokens() API from returning duplicated |
| 109 | // tokens. |
| 110 | // TODO(jaewan): Change this. If developer is really creating two sessions with the same |
| 111 | // id, this will silently invalidate previous session and no way for |
| 112 | // developers to know that. |
| 113 | // Instead, keep the list of static session ids from our APIs. |
| 114 | // Also change Controller2Impl.onConnectionChanged / getController. |
| 115 | // Also clean up ControllerCallback#destroy(). |
| 116 | if (DEBUG) { |
| 117 | Log.d(TAG, "Session is recreated almost immediately. " + this); |
| 118 | } |
| 119 | onSessionDestroyed(); |
| 120 | } |
| 121 | mController = onCreateMediaController(packageName, id, sessionBinder); |
| 122 | mSessionPid = sessionPid; |
| 123 | return mController.getSessionToken(); |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * Called when session becomes active and needs controller to listen session's activeness. |
| 128 | * <p> |
| 129 | * Should be overridden by subclasses to create token with its own extra information. |
| 130 | */ |
| 131 | MediaController2 onCreateMediaController( |
| 132 | String packageName, String id, IMediaSession2 sessionBinder) { |
| 133 | SessionToken token = new SessionToken( |
| 134 | SessionToken.TYPE_SESSION, packageName, id, null, sessionBinder); |
| 135 | return createMediaController(token); |
| 136 | } |
| 137 | |
| 138 | final MediaController2 createMediaController(SessionToken token) { |
| 139 | mControllerCallback = new ControllerCallback(); |
| 140 | return new MediaController2(mContext, token, mControllerCallback, mMainExecutor); |
| 141 | } |
| 142 | |
| 143 | /** |
| 144 | * @return controller. Note that framework can only call oneway calls. |
| 145 | */ |
| 146 | public SessionToken getToken() { |
| 147 | return mController == null ? null : mController.getSessionToken(); |
| 148 | } |
| 149 | |
| 150 | @Override |
| 151 | public String toString() { |
| 152 | return getToken() == null |
| 153 | ? "Token {null}" |
| 154 | : "SessionRecord {pid=" + mSessionPid + ", " + getToken().toString() + "}"; |
| 155 | } |
| 156 | |
| 157 | private class ControllerCallback extends MediaController2.ControllerCallback { |
| 158 | private final AtomicBoolean mIsActive = new AtomicBoolean(true); |
| 159 | |
| 160 | // This is called on the main thread with no lock. So place ensure followings. |
| 161 | // 1. Don't touch anything in the parent class that needs synchronization. |
| 162 | // All other APIs in the MediaSession2Record assumes that server would use them with |
| 163 | // the lock hold. |
| 164 | // 2. This can be called after the controller registered is released. |
| 165 | @Override |
| 166 | public void onDisconnected() { |
| 167 | if (!mIsActive.get()) { |
| 168 | return; |
| 169 | } |
| 170 | if (DEBUG) { |
| 171 | Log.d(TAG, "onDisconnected, token=" + getToken()); |
| 172 | } |
| 173 | mSessionDestroyedListener.onSessionDestroyed(MediaSession2Record.this); |
| 174 | } |
| 175 | |
| 176 | // TODO(jaewan): Remove this API when we revisit createSessionToken() |
| 177 | public void destroy() { |
| 178 | mIsActive.set(false); |
| 179 | } |
| 180 | }; |
| 181 | } |