fixed dangling engine references

Author: nodeful

native/app/Source/Application.swift

@@ -25,13 +25,12 @@ enum VolumeChangeDirection: String {
 }
 
 class Application {
-  // Engine
-  static var sources: Sources!
-  static var effects: Effects!
-  static var volume: Volume!
-  static var engine: Engine!
-  static var output: Output!
-  static var selectedDevice: AudioDevice!
+  static var engine: Engine?
+  static var output: Output?
+  static var engineCreated = EmitterKit.Event<Void>()
+  static var outputCreated = EmitterKit.Event<Void>()
+
+  static var selectedDevice: AudioDevice?
   static var selectedDeviceIsAliveListener: EventListener<AudioDevice>?
   static var selectedDeviceVolumeChangedListener: EventListener<AudioDevice>?
   static var selectedDeviceSampleRateChangedListener: EventListener<AudioDevice>?
@@ -191,7 +190,7 @@ class Application {
         }
       } else if (list.removed.count > 0) {
 
-        let currentDeviceRemoved = list.removed.contains(where: { $0.id == selectedDevice.id })
+        let currentDeviceRemoved = list.removed.contains(where: { $0.id == selectedDevice?.id })
 
         if (currentDeviceRemoved) {
           removeEngines()
@@ -207,7 +206,7 @@ class Application {
     AudioDeviceEvents.on(.isJackConnectedChanged) { device in
       let connected = device.isJackConnected(direction: .playback)
       Console.log("isJackConnectedChanged", device, connected)
-      if (connected == true && device.id != selectedDevice.id) {
+      if (connected == true && device.id != selectedDevice?.id) {
         selectOutput(device: device)
       }
     }
@@ -254,7 +253,7 @@ class Application {
   static func startPassthrough () {
     selectedDevice = AudioDevice.currentOutputDevice
 
-    if (selectedDevice.id == Driver.device!.id) {
+    if (selectedDevice!.id == Driver.device!.id) {
       selectOutput(device: AudioDevice.builtInOutputDevice) // TODO: Replace with a known device from a stack
       return
     }
@@ -267,7 +266,7 @@ class Application {
     Application.dispatchAction(VolumeAction.setBalance(Application.store.state.effects.volume.balance, false))
 
     Driver.device!.setVirtualMasterVolume(volume > 1 ? 1 : Float32(volume), direction: .playback)
-    Driver.latency = selectedDevice.latency(direction: .playback) ?? 0 // Set driver latency to mimic device
+    Driver.latency = selectedDevice!.latency(direction: .playback) ?? 0 // Set driver latency to mimic device
 //    Driver.safetyOffset = selectedDevice.safetyOffset(direction: .playback) ?? 0 // Set driver latency to mimic device
     self.matchDriverSampleRateToOutput()
 
@@ -278,61 +277,58 @@ class Application {
     AudioDevice.currentOutputDevice = Driver.device!
     // TODO: Figure out a better way
     Utilities.delay(1000) {
-      self.createAudioPipeline()
+      createAudioPipeline()
     }
   }
 
   private static func matchDriverSampleRateToOutput () {
-    let outputSampleRate = selectedDevice.actualSampleRate()!
+    let outputSampleRate = selectedDevice!.actualSampleRate()!
     let driverSampleRates = Driver.sampleRates
     let closestSampleRate = driverSampleRates.min( by: { abs($0 - outputSampleRate) < abs($1 - outputSampleRate) } )!
     Driver.device!.setNominalSampleRate(closestSampleRate)
   }
 
   private static func createAudioPipeline () {
-    _ = Sources() { sources in
-      self.sources = sources
-      effects = Effects()
-      engine = Engine(
-        sources: sources,
-        effects: effects
-      )
-      volume = Volume()
-      output = Output(device: selectedDevice, engine: engine, volume: volume)
-      
+    engine = nil
+    engine = Engine {
+      engineCreated.emit()
+      output = nil
+      output = Output(device: selectedDevice!)
+      outputCreated.emit()
+
       selectedDeviceIsAliveListener = AudioDeviceEvents.on(
         .isAliveChanged,
-        onDevice: selectedDevice,
+        onDevice: selectedDevice!,
         retain: false
       ) {
         // If device that we are sending audio to goes offline we need to stop and switch to a different device
-        if (selectedDevice.isAlive() == false) {
+        if (selectedDevice!.isAlive() == false) {
           Console.log("Current device dies so switching to built it")
           selectOutput(device: AudioDevice.builtInOutputDevice) // TODO: Replace with a known device from stack
         }
       }
 
       selectedDeviceSampleRateChangedListener = AudioDeviceEvents.on(
         .nominalSampleRateChanged,
-        onDevice: selectedDevice,
+        onDevice: selectedDevice!,
         retain: false
       ) {
         stopRemoveEngines()
-        Utilities.delay(100) {
+        Utilities.delay(1000) {
           // need a delay, because emitter should finish it's work at first
           try! AudioDeviceEvents.recreateEventEmitters([.isAliveChanged, .volumeChanged, .nominalSampleRateChanged])
-          self.setupDriverDeviceEvents()
-          self.matchDriverSampleRateToOutput()
+          setupDriverDeviceEvents()
+          matchDriverSampleRateToOutput()
           createAudioPipeline()
         }
       }
 
       selectedDeviceVolumeChangedListener = AudioDeviceEvents.on(
         .volumeChanged,
-        onDevice: selectedDevice,
+        onDevice: selectedDevice!,
         retain: false
       ) {
-        let deviceVolume = selectedDevice.virtualMasterVolume(direction: .playback)!
+        let deviceVolume = selectedDevice!.virtualMasterVolume(direction: .playback)!
         let driverVolume = Driver.device!.virtualMasterVolume(direction: .playback)!
         if (deviceVolume != driverVolume) {
           Driver.device!.setVirtualMasterVolume(deviceVolume, direction: .playback)
@@ -371,7 +367,7 @@ class Application {
 
   static var overrideNextVolumeEvent = false
   static func volumeChangeButtonPressed (direction: VolumeChangeDirection, quarterStep: Bool = false) {
-    if volume == nil || engine == nil {
+    if engine == nil || output == nil {
       return
     }
     if direction == .UP {
@@ -380,7 +376,7 @@ class Application {
         ignoreNextDriverMuteEvent = false
       }
     }
-    let gain = volume.gain
+    let gain = output!.volume.gain
     if (gain >= 1) {
       if direction == .DOWN {
         overrideNextVolumeEvent = true
@@ -419,34 +415,29 @@ class Application {
     ignoreNextDriverMuteEvent = false
   }
 
-  private static func killEngine () {
-    engine = nil
-  }
-  
   private static func switchBackToLastKnownDevice () {
     // If the active equalizer global gain hass been lowered we need to equalize the volume to avoid blowing people ears our
-    if (effects != nil && effects.equalizers.active.globalGain < 0) {
-      if (selectedDevice.canSetVirtualMasterVolume(direction: .playback)) {
-        var decibels = selectedDevice.virtualMasterVolumeInDecibels(direction: .playback)!
-        decibels = decibels + Float(self.effects.equalizers.active.globalGain)
-        selectedDevice.setVirtualMasterVolume(selectedDevice.decibelsToScalar(volume: decibels, channel: 1, direction: .playback)!, direction: .playback)
-      } else if (selectedDevice.canSetVolume(channel: 1, direction: .playback)) {
-        var decibels = selectedDevice.volumeInDecibels(channel: 1, direction: .playback)!
-        decibels = decibels + Float(self.effects.equalizers.active.globalGain)
-        for channel in 1...selectedDevice.channels(direction: .playback) {
-          selectedDevice.setVolume(selectedDevice.decibelsToScalar(volume: decibels, channel: channel, direction: .playback)!, channel: channel, direction: .playback)
+    if (engine == nil || selectedDevice == nil) { return }
+    if (engine!.effects != nil && engine!.effects.equalizers.active.globalGain < 0) {
+      if (selectedDevice!.canSetVirtualMasterVolume(direction: .playback)) {
+        var decibels = selectedDevice!.virtualMasterVolumeInDecibels(direction: .playback)!
+        decibels = decibels + Float(engine!.effects.equalizers.active.globalGain)
+        selectedDevice!.setVirtualMasterVolume(selectedDevice!.decibelsToScalar(volume: decibels, channel: 1, direction: .playback)!, direction: .playback)
+      } else if (selectedDevice!.canSetVolume(channel: 1, direction: .playback)) {
+        var decibels = selectedDevice!.volumeInDecibels(channel: 1, direction: .playback)!
+        decibels = decibels + Float(engine!.effects.equalizers.active.globalGain)
+        for channel in 1...selectedDevice!.channels(direction: .playback) {
+          selectedDevice!.setVolume(selectedDevice!.decibelsToScalar(volume: decibels, channel: channel, direction: .playback)!, channel: channel, direction: .playback)
         }
       }
     }
-    if (selectedDevice != nil) {
-      AudioDevice.currentOutputDevice = selectedDevice
-    }
+    AudioDevice.currentOutputDevice = selectedDevice!
   }
 
   static func stopSave () {
     stopListeners()
-    stopRemoveEngines()
     switchBackToLastKnownDevice()
+    stopRemoveEngines()
     Storage.synchronize()
   }
 

native/app/Source/Audio/Effects/Effect.swift

@@ -13,7 +13,7 @@ import AVFoundation
 class Effect {
   var node: AVAudioNode!
   var enabledChanged = Event<Bool>()
-  var engine: Engine?
+
   var name: String {
     return String(describing: self)
   }
@@ -33,12 +33,4 @@ class Effect {
     }
   }
 
-  func wasAttachedTo (engine: Engine) {
-    self.engine = engine
-  }
-  
-  func wasDetachedFrom (engine: Engine) {
-    self.engine = nil
-  }
-  
 }

native/app/Source/Audio/Engine.swift

@@ -12,11 +12,13 @@ import AMCoreAudio
 import AVFoundation
 import Foundation
 import AudioToolbox
+import EmitterKit
 
 class Engine {
-  private var eventListeners: [Any] = []
-  let sources: Sources
-  let effects: Effects
+  private var equalizersTypeChangedListener: EventListener<EqualizerType>?
+
+  let sources: Sources!
+  let effects: Effects!
   var attachedEqualizer: Equalizer?
 
   var format: AVAudioFormat!
@@ -27,17 +29,21 @@ class Engine {
   // Middleware
   var buffer: CircularBuffer<Float>!
 
-  init (sources: Sources, effects: Effects) {
+  init (_ completion: @escaping () -> Void) {
     Console.log("Creating Engine")
-    self.sources = sources
-    self.effects = effects
-    setupEngine()
-    setupSink()
-    setupBuffer()
-    attach()
-    chain()
-    setupListeners()
-    start()
+    self.effects = Effects()
+    self.sources = Sources()
+    Sources.getInputPermission() {
+      self.sources.initializeSystem()
+      self.setupEngine()
+      self.setupSink()
+      self.setupBuffer()
+      self.attach()
+      self.chain()
+      self.setupListeners()
+      self.start()
+      completion()
+    }
   }
 
   private func setupEngine () {
@@ -59,8 +65,9 @@ class Engine {
   }
 
   private func attachSource () {
-    sources.system.setInputDevice(engine: engine)
+    engine.setInputDevice(sources.system.device)
     format = engine.inputNode.inputFormat(forBus: 0)
+    Console.log("Set Input Engine format to: \(format.description)")
   }
 
   private func attachEffects () {
@@ -70,13 +77,11 @@ class Engine {
   private func attachEqualizer () {
     engine.attach(effects.equalizers.active.eq)
     attachedEqualizer = effects.equalizers.active
-    effects.equalizers.active.wasAttachedTo(engine: self)
   }
 
   private func detachEqualizer () {
     if attachedEqualizer != nil {
       engine.detach(attachedEqualizer!.eq)
-      attachedEqualizer?.wasDetachedFrom(engine: self)
       attachedEqualizer = nil
     }
   }
@@ -94,7 +99,7 @@ class Engine {
   }
 
   private func chainSourceToEffects () {
-    Console.log("Chaining Source to Volume")
+    Console.log("Chaining Source to Effects")
     engine.connect(engine.inputNode, to: effects.equalizers.active.eq, format: format)
   }
 
@@ -111,45 +116,47 @@ class Engine {
     let lastAVUnit = effects.equalizers.active.eq as AVAudioUnit
     if let err = checkErr(AudioUnitAddRenderNotify(lastAVUnit.audioUnit,
                                                    renderCallback,
-                                                   UnsafeMutableRawPointer(Unmanaged<Engine>.passUnretained(self).toOpaque()))) {
+                                                   nil)) {
       Console.log(err)
       return
     }
   }
 
   let renderCallback: AURenderCallback = {
     (inRefCon: UnsafeMutableRawPointer,
-    ioActionFlags: UnsafeMutablePointer<AudioUnitRenderActionFlags>,
-    inTimeStamp:  UnsafePointer<AudioTimeStamp>,
-    inBusNumber: UInt32,
-    inNumberFrames: UInt32,
-    ioData: UnsafeMutablePointer<AudioBufferList>?) -> OSStatus in
+     ioActionFlags: UnsafeMutablePointer<AudioUnitRenderActionFlags>,
+     inTimeStamp:  UnsafePointer<AudioTimeStamp>,
+     inBusNumber: UInt32,
+     inNumberFrames: UInt32,
+     ioData: UnsafeMutablePointer<AudioBufferList>?) -> OSStatus in
 
     if ioActionFlags.pointee == AudioUnitRenderActionFlags.unitRenderAction_PostRender {
-      let engine = Unmanaged<Engine>.fromOpaque(inRefCon).takeUnretainedValue()
+      if Application.engine == nil { return noErr }
 
       let sampleTime = inTimeStamp.pointee.mSampleTime
 
       let start = sampleTime.int64Value
       let end = start + Int64(inNumberFrames)
-      if engine.buffer.write(from: ioData!, start: start, end: end) != .noError {
+      if Application.engine!.buffer.write(from: ioData!, start: start, end: end) != .noError {
         return OSStatus()
       }
-      engine.lastSampleTime = sampleTime
+      Application.engine!.lastSampleTime = sampleTime
     }
 
     return noErr
   }
 
   private func setupListeners () {
-    eventListeners.append(Equalizers.typeChanged.on { _ in
-      self.stop()
-      Utilities.delay(100) {
-        self.reattachEqualizer()
-        self.chain()
-        self.start()
+    equalizersTypeChangedListener = Equalizers.typeChanged.on { [weak self] _ in
+      if self == nil { return }
+      self!.stop()
+      Utilities.delay(100) { [weak self] in
+        if self == nil { return }
+        self!.reattachEqualizer()
+        self!.chain()
+        self!.start()
       }
-    })
+    }
   }
 
   private func start () {
@@ -164,5 +171,9 @@ class Engine {
   func stop () {
     self.engine.stop()
   }
-  
+
+  deinit {
+    equalizersTypeChangedListener?.isListening = false
+    equalizersTypeChangedListener = nil
+  }
 }