SoundBoard/MegaDrone: Retry open if it fails (#1664)

4 files changed, 59 insertions, 10 deletions

diff --git a/samples/MegaDrone/src/main/cpp/MegaDroneEngine.cpp b/samples/MegaDrone/src/main/cpp/MegaDroneEngine.cpp
index 26c36013..df3309ef 100644
--- a/samples/MegaDrone/src/main/cpp/MegaDroneEngine.cpp
+++ b/samples/MegaDrone/src/main/cpp/MegaDroneEngine.cpp
@@ -76,17 +76,41 @@ void MegaDroneEngine::createCallback(std::vector<int> cpuIds){
     mDataCallback->setThreadAffinityEnabled(true);
 }
 
-bool MegaDroneEngine::start(){
+bool MegaDroneEngine::start() {
+    // It is possible for a stream's device to become disconnected during stream open or between
+    // stream open and stream start.
+    // If the stream fails to start, close the old stream and try again.
+    bool didStart = false;
+    int tryCount = 0;
+    do {
+        if (tryCount > 0) {
+            usleep(20 * 1000); // Sleep between tries to give the system time to settle.
+        }
+        didStart = attemptStart();
+    } while (!didStart && tryCount++ < 3);
+    if (!didStart) {
+        LOGE("Failed at starting the stream");
+    }
+    return didStart;
+}
+
+bool MegaDroneEngine::attemptStart() {
     auto result = createPlaybackStream();
-    if (result == Result::OK){
+
+    if (result == Result::OK) {
         // Create our synthesizer audio source using the properties of the stream
         mAudioSource = std::make_shared<Synth>(mStream->getSampleRate(), mStream->getChannelCount());
         mDataCallback->reset();
         mDataCallback->setSource(std::dynamic_pointer_cast<IRenderableAudio>(mAudioSource));
-        mStream->start();
-        return true;
+        result = mStream->start();
+        if (result == Result::OK) {
+            return true;
+        } else {
+            LOGW("Failed attempt at starting the playback stream. Error: %s", convertToText(result));
+            return false;
+        }
     } else {
-        LOGE("Failed to create the playback stream. Error: %s", convertToText(result));
+        LOGW("Failed attempt at creating the playback stream. Error: %s", convertToText(result));
         return false;
     }
 }
diff --git a/samples/MegaDrone/src/main/cpp/MegaDroneEngine.h b/samples/MegaDrone/src/main/cpp/MegaDroneEngine.h
index 841ec2d4..17205224 100644
--- a/samples/MegaDrone/src/main/cpp/MegaDroneEngine.h
+++ b/samples/MegaDrone/src/main/cpp/MegaDroneEngine.h
@@ -50,6 +50,7 @@ private:
     std::shared_ptr<DefaultDataCallback> mDataCallback;
     std::shared_ptr<DefaultErrorCallback> mErrorCallback;
 
+    bool attemptStart();
     oboe::Result createPlaybackStream();
     void createCallback(std::vector<int> cpuIds);
 };
diff --git a/samples/SoundBoard/src/main/cpp/SoundBoardEngine.cpp b/samples/SoundBoard/src/main/cpp/SoundBoardEngine.cpp
index 193e3a14..defb6dcb 100644
--- a/samples/SoundBoard/src/main/cpp/SoundBoardEngine.cpp
+++ b/samples/SoundBoard/src/main/cpp/SoundBoardEngine.cpp
@@ -80,18 +80,41 @@ void SoundBoardEngine::createCallback(int32_t numSignals){
     mNumSignals = numSignals;
 }
 
-bool SoundBoardEngine::start(){
+bool SoundBoardEngine::start() {
+    // It is possible for a stream's device to become disconnected during stream open or between
+    // stream open and stream start.
+    // If the stream fails to start, close the old stream and try again.
+    bool didStart = false;
+    int tryCount = 0;
+    do {
+        if (tryCount > 0) {
+            usleep(20 * 1000); // Sleep between tries to give the system time to settle.
+        }
+        didStart = attemptStart();
+    } while (!didStart && tryCount++ < 3);
+    if (!didStart) {
+        LOGE("Failed at starting the stream");
+    }
+    return didStart;
+}
+
+bool SoundBoardEngine::attemptStart() {
     auto result = createPlaybackStream();
 
-    if (result == Result::OK){
+    if (result == Result::OK) {
         // Create our synthesizer audio source using the properties of the stream
         mSynth = Synth::create(mStream->getSampleRate(), mStream->getChannelCount(), mNumSignals);
         mDataCallback->reset();
         mDataCallback->setSource(std::dynamic_pointer_cast<IRenderableAudio>(mSynth));
-        mStream->start();
-        return true;
+        result = mStream->start();
+        if (result == Result::OK) {
+            return true;
+        } else {
+            LOGW("Failed attempt at starting the playback stream. Error: %s", convertToText(result));
+            return false;
+        }
     } else {
-        LOGE("Failed to create the playback stream. Error: %s", convertToText(result));
+        LOGW("Failed attempt at creating the playback stream. Error: %s", convertToText(result));
         return false;
     }
 }
diff --git a/samples/SoundBoard/src/main/cpp/SoundBoardEngine.h b/samples/SoundBoard/src/main/cpp/SoundBoardEngine.h
index 4d093506..033f839f 100644
--- a/samples/SoundBoard/src/main/cpp/SoundBoardEngine.h
+++ b/samples/SoundBoard/src/main/cpp/SoundBoardEngine.h
@@ -56,6 +56,7 @@ private:
     std::shared_ptr<DefaultDataCallback> mDataCallback;
     std::shared_ptr<DefaultErrorCallback> mErrorCallback;
 
+    bool attemptStart();
     oboe::Result createPlaybackStream();
     void createCallback(int32_t numSignals);
 };