Move ownership of AudioEngine object into Java
diff --git a/samples/MegaDrone/src/main/cpp/native-lib.cpp b/samples/MegaDrone/src/main/cpp/native-lib.cpp
index aaca8b7..294790d 100644
--- a/samples/MegaDrone/src/main/cpp/native-lib.cpp
+++ b/samples/MegaDrone/src/main/cpp/native-lib.cpp
@@ -19,8 +19,7 @@
#include <vector>
#include "AudioEngine.h"
-
-std::unique_ptr<AudioEngine> engine;
+#include "../../../../../src/common/OboeDebug.h"
std::vector<int> convertJavaArrayToVector(JNIEnv *env, jintArray intArray){
@@ -37,26 +36,70 @@
return v;
}
-extern "C"
-JNIEXPORT void JNICALL
-Java_com_example_oboe_megadrone_MainActivity_startEngine(JNIEnv *env, jobject instance,
+extern "C" {
+
+/**
+ * Start the audio engine
+ *
+ * @param env
+ * @param instance
+ * @param jCpuIds - CPU core IDs which the audio process should affine to
+ * @return a pointer to the audio engine. This should be passed to other methods
+ */
+JNIEXPORT jlong JNICALL
+Java_com_example_oboe_megadrone_MainActivity_startEngine(JNIEnv *env, jobject /*unused*/,
jintArray jCpuIds) {
- engine = std::make_unique<AudioEngine>();
- std::vector<int> cpuIds = convertJavaArrayToVector(env, jCpuIds);
- engine->start(cpuIds);
+ // We use std::nothrow so `new` returns a nullptr if the engine creation fails
+ AudioEngine *engine = new(std::nothrow) AudioEngine();
+ if (engine) {
+ std::vector<int> cpuIds = convertJavaArrayToVector(env, jCpuIds);
+ engine->start(cpuIds);
+ LOGD("Engine started");
+ } else {
+ LOGE("Failed to create audio engine");
+ }
+ return reinterpret_cast<jlong>(engine);
}
-extern "C"
+/**
+ * Stop the audio engine
+ *
+ * @param env
+ * @param instance
+ * @param jEngineHandle - pointer to the audio engine
+ */
JNIEXPORT void JNICALL
-Java_com_example_oboe_megadrone_MainActivity_stopEngine(JNIEnv *env, jobject instance) {
-
- engine->stop();
+Java_com_example_oboe_megadrone_MainActivity_stopEngine( JNIEnv * /*unused*/, jobject /*unused*/,
+ jlong jEngineHandle) {
+ auto *engine = reinterpret_cast<AudioEngine *>(jEngineHandle);
+ if (engine) {
+ engine->stop();
+ delete engine;
+ LOGD("Engine stopped");
+ } else {
+ LOGE("Engine handle is invalid, call startEngine() to create a new one");
+ return;
+ }
}
-
-extern "C"
+/**
+ * Send a tap event to the audio engine
+ *
+ * @param env
+ * @param instance
+ * @param jEngineHandle - pointer to audio engine
+ * @param isDown - true if user is tapping down on screen, false user is lifting finger off screen
+ */
JNIEXPORT void JNICALL
-Java_com_example_oboe_megadrone_MainActivity_tap(JNIEnv *env, jobject instance, jboolean b) {
+Java_com_example_oboe_megadrone_MainActivity_tap(JNIEnv * /*unused*/, jobject /*unused*/,
+ jlong jEngineHandle,
+ jboolean isDown) {
+ auto *engine = reinterpret_cast<AudioEngine *>(jEngineHandle);
+ if (engine){
+ engine->tap(isDown);
+ } else {
+ LOGE("Engine handle is invalid, call createEngine() to create a new one");
+ }
+}
- engine->tap(b);
-}
\ No newline at end of file
+} // extern "C"
\ No newline at end of file
diff --git a/samples/MegaDrone/src/main/java/com/example/oboe/megadrone/MainActivity.java b/samples/MegaDrone/src/main/java/com/example/oboe/megadrone/MainActivity.java
index 4c8f6b5..b1a8424 100644
--- a/samples/MegaDrone/src/main/java/com/example/oboe/megadrone/MainActivity.java
+++ b/samples/MegaDrone/src/main/java/com/example/oboe/megadrone/MainActivity.java
@@ -25,6 +25,11 @@
public class MainActivity extends AppCompatActivity {
private final String TAG = MainActivity.class.toString();
+ private static long mEngineHandle = 0;
+
+ private native long startEngine(int[] cpuIds);
+ private native void stopEngine(long engineHandle);
+ private native void tap(long engineHandle, boolean isDown);
// Used to load the 'native-lib' library on application startup.
static {
@@ -35,32 +40,29 @@
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
+
}
+ @Override
protected void onResume(){
+ mEngineHandle = startEngine(getExclusiveCores());
super.onResume();
- startEngine(getExclusiveCores());
}
+ @Override
protected void onPause(){
- stopEngine();
+ stopEngine(mEngineHandle);
super.onPause();
}
- private native void stopEngine();
-
- private native void startEngine(int[] cpuIds);
-
@Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN){
- tap(true);
+ tap(mEngineHandle, true);
} else if (event.getAction() == MotionEvent.ACTION_UP){
- tap(false);
+ tap(mEngineHandle, false);
}
-
-
return super.onTouchEvent(event);
}
@@ -68,7 +70,7 @@
// bound to these cores to avoids the risk of it being migrated to slower or more contended
// core(s).
private int[] getExclusiveCores(){
- int exclusiveCores[] = {};
+ int[] exclusiveCores = {};
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
Log.w(TAG, "getExclusiveCores() not supported. Only available on API " +
@@ -82,10 +84,6 @@
}
return exclusiveCores;
}
-
- private native void tap(boolean b);
-
-
}
