Allow delayed execution of deallocation operations by waiting engine idle phase

gradle.properties

@@ -17,3 +17,5 @@ org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
 android.useAndroidX=true
 # Automatically convert third-party libraries to use AndroidX
 android.enableJetifier=true
+android.nonTransitiveRClass=false
+android.nonFinalResIds=false

gradle/wrapper/gradle-wrapper.properties

@@ -1 +1 @@
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.2-all.zip

mwengine/CMakeLists.txt

@@ -34,7 +34,7 @@ set(target mwengine)
 # architecture-specific compiler flags
 
 if (${ANDROID_ABI} MATCHES "x86_64")
-    SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=x86-64 -msse4.2 -mpopcnt -m64 -mtune=intel")
+    SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=x86-64 -msse4.2 -mpopcnt -m64")
 endif()
 
 # source folders

mwengine/build.gradle

@@ -7,12 +7,13 @@ buildscript {
         maven { url 'https://jitpack.io' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.1.3'
+        classpath 'com.android.tools.build:gradle:8.2.1'
     }
 }
 
 android {
-    compileSdkVersion 32
+    namespace 'nl.igorski.mwengine'
+    compileSdk 33
 
     defaultConfig {
         // NOTE: the value of minSdkVersion is used by the native build as the target APP_PLATFORM
@@ -22,7 +23,7 @@ android {
         // thus set the value of minSdkVersion to whatever fits your use case.
 
         minSdkVersion 16
-        targetSdkVersion 32
+        targetSdkVersion 33
 
         ndk {
             abiFilters "armeabi-v7a", "arm64-v8a", "x86", "x86_64"

mwengine/src/main/AndroidManifest.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="nl.igorski.mwengine">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <uses-feature android:name="android.hardware.audio.output" />
 

mwengine/src/main/cpp/audioengine.cpp

@@ -1,7 +1,7 @@
 /**
  * The MIT License (MIT)
  *
- * Copyright (c) 2013-2022 Igor Zinken - https://www.igorski.nl
+ * Copyright (c) 2013-2024 Igor Zinken - https://www.igorski.nl
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -77,6 +77,7 @@ namespace MWEngine {
     int   AudioEngine::time_sig_beat_unit         = 4;
     int   AudioEngine::queuedTime_sig_beat_amount = time_sig_beat_amount;
     int   AudioEngine::queuedTime_sig_beat_unit   = time_sig_beat_unit;
+    bool  AudioEngine::broadcast_idle = false;
 
     /* buffer read/write pointers */
 
@@ -745,6 +746,12 @@ namespace MWEngine {
         if ( recordingState.bouncing && AudioEngineProps::isRendering.load() && DriverAdapter::isAAudio() ) {
             render( amountOfSamples );
         }
+
+        if ( broadcast_idle ) {
+            broadcast_idle = false;
+            Notifier::broadcast( Notifications::ENGINE_IDLE );
+        }
+
         return AudioEngineProps::isRendering.load();
     }
 
@@ -762,6 +769,11 @@ namespace MWEngine {
 #endif
     }
 
+    void AudioEngine::notifyWhenIdle()
+    {
+        broadcast_idle = true;
+    }
+
     void AudioEngine::handleTempoUpdate( float aQueuedTempo, bool broadcastUpdate )
     {
         float ratio = 1;

mwengine/src/main/cpp/audioengine.h

@@ -1,7 +1,7 @@
 /**
  * The MIT License (MIT)
  *
- * Copyright (c) 2013-2022 Igor Zinken - https://www.igorski.nl
+ * Copyright (c) 2013-2024 Igor Zinken - https://www.igorski.nl
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -49,6 +49,7 @@ class AudioEngine
         static void start( Drivers::types audioDriver );
         static void stop();
         static void reset();
+        static void notifyWhenIdle(); // request to be notified when engine reaches idle state after render (fires once per request)
 
         static AudioChannel* getInputChannel();
 
@@ -143,6 +144,8 @@ class AudioEngine
         static int min_step_position;      // the lowest step in the current sequence
         static int max_step_position;      // the maximum step in the current sequence (e.g. 15 for single measure using a 16 step sequencer - step starts at 0.)
 
+        static bool broadcast_idle; // whether to broadcast a notification when the engine is entering idle phase after render
+
         /* buffer read/write pointers */
 
         static int bufferPosition; // the current sequence position in samples ("playback head" offset)

mwengine/src/main/cpp/definitions/notifications.h

@@ -1,7 +1,7 @@
 /**
  * The MIT License (MIT)
  *
- * Copyright (c) 2015-2018 Igor Zinken - http://www.igorski.nl
+ * Copyright (c) 2015-2024 Igor Zinken - https://www.igorski.nl
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -52,6 +52,7 @@ class Notifications
             /* system messages */
 
             STATUS_BRIDGE_CONNECTED,    // JNI bridge connected
+            ENGINE_IDLE,                // engine is currently in idle state (between render cycles), this is the time to safely clean up resources
 
             /* fatal errors */
 

mwengine/src/main/cpp/events/baseaudioevent.cpp

@@ -54,8 +54,21 @@ BaseAudioEvent::~BaseAudioEvent()
 
 void BaseAudioEvent::dispose()
 {
-    removeFromSequencer();
-    destroyBuffer();
+    _disposed = true; // set the disposed flag as removal can be async when sequencer is running
+    _enabled  = false;
+
+    if ( _instrument != nullptr && isSequenced ) {
+        _instrument->removeEvent( this, false );
+    } else {
+        stop();
+    }
+}
+
+void BaseAudioEvent::onRemove()
+{
+    if ( _disposed ) {
+        destroyBuffer(); // if event was removed as part of disposal routine, clean the buffer now
+    }
 }
 
 BaseInstrument* BaseAudioEvent::getInstrument()

mwengine/src/main/cpp/events/baseaudioevent.h

@@ -35,7 +35,8 @@ class BaseAudioEvent
         BaseAudioEvent();
         virtual ~BaseAudioEvent();
 
-        void dispose(); // invoke when removing the Event from the engine
+        void dispose();  // invoke when removing the Event from the engine, should be done when ENGINE_IDLE is broadcast!
+        void onRemove(); // invoked by the Instrument once the event has safely been removed
 
         /**
          * event volume is in a percentile (0 - 1) range
@@ -213,6 +214,7 @@ class BaseAudioEvent
         bool _removalEnqueued;
         bool _locked;
         bool _updateAfterUnlock; // use in update-methods when checking for lock
+        bool _disposed = false;
 
         // _destroyableBuffer indicates we can delete the buffer on destruction (true by default and
         // implies that this AudioEvent holds the only reference to its buffers

mwengine/src/main/cpp/instruments/baseinstrument.cpp

@@ -175,6 +175,9 @@ bool BaseInstrument::removeEvent( BaseAudioEvent* audioEvent, bool isLiveEvent )
             removeEventFromMeasureCache( audioEvent );
         }
     }
+    if ( removed ) {
+        audioEvent->onRemove();
+    }
     return removed;
 }
 

mwengine/src/main/cpp/sequencer.cpp

@@ -1,7 +1,7 @@
 /**
  * The MIT License (MIT)
  *
- * Copyright (c) 2013-2022 Igor Zinken - https://www.igorski.nl
+ * Copyright (c) 2013-2024 Igor Zinken - https://www.igorski.nl
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -45,6 +45,7 @@ int Sequencer::registerInstrument( BaseInstrument* instrument )
     for ( auto const & i : instruments ) {
         if ( i == instrument ) {
             wasPresent = true;
+            break;
         }
     }
 
@@ -112,9 +113,9 @@ bool Sequencer::getAudioEvents( std::vector<AudioChannel*>* channels, int buffer
                 }
             }
 
-            if ( addLiveInstruments && instrument->hasLiveEvents() )
+            if ( addLiveInstruments && instrument->hasLiveEvents() ) {
                 collectLiveEvents( instrument );
-
+            }
             channels->push_back( instrumentChannel );
         }
     }
@@ -133,7 +134,6 @@ void Sequencer::collectSequencedEvents( BaseInstrument* instrument, int bufferPo
     if ( !instrument->hasEvents() ) {
         return;
     }
-
     AudioChannel* channel = instrument->audioChannel;
 
     auto audioEvents = instrument->getEventsForMeasure( measure );

mwengine/src/main/cpp/sequencercontroller.cpp

@@ -1,7 +1,7 @@
 /**
  * The MIT License (MIT)
  *
- * Copyright (c) 2013-2022 Igor Zinken - https://www.igorski.nl
+ * Copyright (c) 2013-2024 Igor Zinken - https://www.igorski.nl
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -86,6 +86,11 @@ void SequencerController::setVolume( float aVolume )
     AudioEngine::volume = VolumeUtil::toLog( aVolume );
 }
 
+bool SequencerController::getPlaying()
+{
+    return Sequencer::playing;
+}
+
 void SequencerController::setPlaying( bool aIsPlaying )
 {
     Sequencer::playing = aIsPlaying;

mwengine/src/main/cpp/sequencercontroller.h

@@ -1,7 +1,7 @@
 /**
  * The MIT License (MIT)
  *
- * Copyright (c) 2013-2022 Igor Zinken - http://www.igorski.nl
+ * Copyright (c) 2013-2024 Igor Zinken - https://www.igorski.nl
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -44,6 +44,7 @@ class SequencerController
         void setTempo   ( float aTempo, int aTimeSigBeatAmount, int aTimeSigBeatUnit );
         void setTempoNow( float aTempo, int aTimeSigBeatAmount, int aTimeSigBeatUnit );
         void setVolume  ( float aVolume );
+        bool getPlaying ();
         void setPlaying ( bool aPlaying );
 
         /**

mwengine/src/main/java/nl/igorski/mwengine/MWEngine.java

@@ -1,7 +1,7 @@
 /**
  * The MIT License (MIT)
  *
- * Copyright (c) 2013-2022 Igor Zinken - https://www.igorski.nl
+ * Copyright (c) 2013-2024 Igor Zinken - https://www.igorski.nl
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -34,6 +34,10 @@
 import android.util.Log;
 import android.view.WindowManager;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
 import nl.igorski.mwengine.core.*;
 
 public final class MWEngine
@@ -77,6 +81,10 @@ public interface IObserver
         void handleNotification( int aNotificationId, int aNotificationValue );
     }
 
+    public interface VoidInterface {
+        public void operation();
+    }
+
     private static MWEngine INSTANCE; // we only allow a single instance to be constructed for resource optimization
     private IObserver _observer;
 
@@ -96,6 +104,8 @@ public interface IObserver
 
     private boolean _initialCreation     = true;
     private boolean _isRunning           = false;
+    private List<VoidInterface> _idleCallbacks  = new ArrayList( Collections.emptyList());
+    private static int ENGINE_IDLE_NOTIFICATION = Notifications.ids.ENGINE_IDLE.ordinal();
 
     /**
      * The Java-side bridge to manage all native layer components
@@ -373,6 +383,20 @@ public void saveRecordedSnippet( int snippetBufferIndex ) {
         AudioEngine.saveRecordedSnippet( snippetBufferIndex );
     }
 
+    /**
+     * Delay execution of provided callback until the engine is idle, e.g.
+     * between render cycles. This can be used to safely dispose() of sequenced AudioEvents
+     * and deallocate referenced resources while the Sequencer is running.
+     */
+    public void executeWhenIdle( VoidInterface callback ) {
+        if ( _sequencerController.getPlaying()) {
+            _idleCallbacks.add( callback );
+            AudioEngine.notifyWhenIdle();
+        } else {
+            callback.operation();
+        }
+    }
+
     public void reset() {
         AudioEngine.reset();
     }
@@ -465,7 +489,17 @@ public static void handleBridgeConnected( int aSomething ) {
     }
 
     public static void handleNotification( int aNotificationId ) {
-        if ( INSTANCE != null && INSTANCE._observer != null ) INSTANCE._observer.handleNotification( aNotificationId );
+        if ( INSTANCE != null ) {
+            if ( ENGINE_IDLE_NOTIFICATION == aNotificationId ) {
+                for ( VoidInterface callback : INSTANCE._idleCallbacks ) {
+                    callback.operation();
+                }
+                INSTANCE._idleCallbacks.clear();
+            }
+            if ( INSTANCE._observer != null ) {
+                INSTANCE._observer.handleNotification( aNotificationId );
+            }
+        }
     }
 
     public static void handleNotificationWithData( int aNotificationId, int aNotificationData ) {

mwengine_example/build.gradle

@@ -19,12 +19,13 @@ buildscript {
         maven { url 'https://jitpack.io' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.1.3'
+        classpath 'com.android.tools.build:gradle:8.2.1'
     }
 }
 
 android {
-    compileSdkVersion 32
+    namespace 'nl.igorski.mwengine.example'
+    compileSdk 33
 
     defaultConfig {
         // the sdk version range below matches the one of the library. You can change these as you see fit
@@ -34,7 +35,7 @@ android {
         // thus set the value of minSdkVersion to whatever fits your use case.
 
         minSdkVersion 16
-        targetSdkVersion 32
+        targetSdkVersion 33
         versionCode 1
         versionName "1.0.0"
 

mwengine_example/src/main/AndroidManifest.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="nl.igorski.mwengine.example">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <!-- required audio related permissions are provided by manifest inside MWEngine library -->