| /* |
| * Copyright (C) 2020 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.soundtrigger_middleware; |
| |
| import android.media.ICaptureStateListener; |
| import android.os.IBinder; |
| import android.os.Parcel; |
| import android.os.RemoteException; |
| import android.os.ServiceManager; |
| import android.util.Log; |
| |
| import java.util.concurrent.Semaphore; |
| import java.util.function.Consumer; |
| |
| /** |
| * This is a never-give-up listener for sound trigger external capture state notifications, as |
| * published by the audio policy service. |
| * |
| * This class will constantly try to connect to the service over a background thread and tolerate |
| * its death. The client will be notified by a single provided function that is called in a |
| * synchronized manner. |
| * For simplicity, there is currently no way to stop the tracker. This is possible to add if the |
| * need ever arises. |
| */ |
| class ExternalCaptureStateTracker { |
| private static final String TAG = "CaptureStateTracker"; |
| /** Our client's listener. */ |
| private final Consumer<Boolean> mListener; |
| /** This semaphore will get a permit every time we need to reconnect. */ |
| private final Semaphore mNeedToConnect = new Semaphore(1); |
| |
| /** |
| * Constructor. Will start a background thread to do the work. |
| * |
| * @param listener A client provided listener that will be called on state |
| * changes. May be |
| * called multiple consecutive times with the same value. Never |
| * called |
| * concurrently. |
| */ |
| ExternalCaptureStateTracker(Consumer<Boolean> listener) { |
| mListener = listener; |
| new Thread(this::run).start(); |
| } |
| |
| /** |
| * Routine for the background thread. Keeps trying to reconnect. |
| */ |
| private void run() { |
| while (true) { |
| mNeedToConnect.acquireUninterruptibly(); |
| connect(); |
| } |
| } |
| |
| /** |
| * Connect to the service, install listener and death notifier. |
| */ |
| private native void connect(); |
| |
| /** |
| * Called by native code to invoke the client listener. |
| * |
| * @param active true when external capture is active. |
| */ |
| private void setCaptureState(boolean active) { |
| mListener.accept(active); |
| } |
| |
| /** |
| * Called by native code when the remote service died. |
| */ |
| private void binderDied() { |
| Log.w(TAG, "Audio policy service died"); |
| mNeedToConnect.release(); |
| } |
| } |