| /* |
| * 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.annotation.NonNull; |
| import android.util.Log; |
| |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.concurrent.Semaphore; |
| |
| /** |
| * 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. |
| */ |
| class ExternalCaptureStateTracker implements ICaptureStateNotifier { |
| private static final String TAG = "CaptureStateTracker"; |
| |
| /** Our client's listeners. Also used as lock. */ |
| private final List<Listener> mListeners = new LinkedList<>(); |
| |
| /** Conservatively, until notified otherwise, we assume capture is active. */ |
| private boolean mCaptureActive = true; |
| |
| /** 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. |
| */ |
| ExternalCaptureStateTracker() { |
| new Thread(this::run).start(); |
| } |
| |
| |
| @Override |
| public boolean registerListener(@NonNull Listener listener) { |
| synchronized (mListeners) { |
| mListeners.add(listener); |
| return mCaptureActive; |
| } |
| } |
| |
| @Override |
| public void unregisterListener(Listener listener) { |
| synchronized (mListeners) { |
| mListeners.remove(listener); |
| } |
| } |
| |
| /** |
| * 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) { |
| try { |
| synchronized (mListeners) { |
| mCaptureActive = active; |
| for (Listener listener : mListeners) { |
| listener.onCaptureStateChange(active); |
| } |
| } |
| } catch (Exception e) { |
| Log.e(TAG, "Exception caught while setting capture state", e); |
| } |
| } |
| |
| /** |
| * Called by native code when the remote service died. |
| */ |
| private void binderDied() { |
| Log.w(TAG, "Audio policy service died"); |
| mNeedToConnect.release(); |
| } |
| } |