Handle stream disconnects

Author: dturner

app/src/main/cpp/AudioEngine.cpp

@@ -15,6 +15,8 @@
  */
 #include <android/log.h>
 #include "AudioEngine.h"
+#include <thread>
+#include <mutex>
 
 aaudio_data_callback_result_t dataCallback(
         AAudioStream *stream,
@@ -26,6 +28,16 @@ aaudio_data_callback_result_t dataCallback(
     return AAUDIO_CALLBACK_RESULT_CONTINUE;
 }
 
+void errorCallback(AAudioStream *stream,
+                   void *userData,
+                   aaudio_result_t error){
+    if (error == AAUDIO_ERROR_DISCONNECTED){
+        std::function<void(void)> restartFunction = std::bind(&AudioEngine::restart,
+                                                            static_cast<AudioEngine *>(userData));
+        new std::thread(restartFunction);
+    }
+}
+
 AudioEngine::AudioEngine() {
     oscillator_ = new Oscillator();
 }
@@ -37,6 +49,7 @@ bool AudioEngine::start() {
     AAudioStreamBuilder_setChannelCount(streamBuilder, 1);
     AAudioStreamBuilder_setPerformanceMode(streamBuilder, AAUDIO_PERFORMANCE_MODE_LOW_LATENCY);
     AAudioStreamBuilder_setDataCallback(streamBuilder, ::dataCallback, oscillator_);
+    AAudioStreamBuilder_setErrorCallback(streamBuilder, ::errorCallback, this);
 
     // Opens the stream.
     aaudio_result_t result = AAudioStreamBuilder_openStream(streamBuilder, &stream_);
@@ -69,6 +82,16 @@ void AudioEngine::stop() {
     }
 }
 
+void AudioEngine::restart(){
+
+    static std::mutex restartingLock;
+    if (restartingLock.try_lock()){
+        stop();
+        start();
+        restartingLock.unlock();
+    }
+}
+
 void AudioEngine::setToneOn(bool isToneOn) {
     oscillator_->setWaveOn(isToneOn);
 }

app/src/main/cpp/AudioEngine.h

@@ -28,6 +28,8 @@ class AudioEngine {
 
     void stop();
 
+    void restart();
+
     void setToneOn(bool isToneOn);
 
 private: