fix audio thread deadlocks

src/Audio/AudioDevice.cs

@@ -28,7 +28,7 @@ namespace MoonWorks.Audio
 		}
 
 		private readonly List<WeakReference<AudioResource>> resources = new List<WeakReference<AudioResource>>();
-		private readonly List<WeakReference<StreamingSound>> streamingSounds = new List<WeakReference<StreamingSound>>();
+		private readonly List<StreamingSound> streamingSounds = new List<StreamingSound>();
 
 		private AudioTweenPool AudioTweenPool = new AudioTweenPool();
 		private readonly List<AudioTween> AudioTweens = new List<AudioTween>();
@@ -39,7 +39,7 @@ namespace MoonWorks.Audio
 		private long previousTickTime;
 		private Thread Thread;
 		private AutoResetEvent WakeSignal;
-		private readonly object StateLock = new object();
+		internal readonly object StateLock = new object();
 
 		private bool IsDisposed;
 
@@ -152,15 +152,7 @@ namespace MoonWorks.Audio
 
 			for (var i = streamingSounds.Count - 1; i >= 0; i--)
 			{
-				var weakReference = streamingSounds[i];
+				streamingSounds[i].Update();
-				if (weakReference.TryGetTarget(out var streamingSound))
-				{
-					streamingSound.Update();
-				}
-				else
-				{
-					streamingSounds.RemoveAt(i);
-				}
 			}
 
 			for (var i = AudioTweens.Count - 1; i >= 0; i--)
@@ -262,7 +254,12 @@ namespace MoonWorks.Audio
 
 		private void AddDynamicSoundInstance(StreamingSound instance)
 		{
-			streamingSounds.Add(new WeakReference<StreamingSound>(instance));
+			streamingSounds.Add(instance);
+		}
+
+		private void RemoveDynamicSoundInstance(StreamingSound reference)
+		{
+			streamingSounds.Remove(reference);
 		}
 
 		internal void AddResourceReference(AudioResource resource, WeakReference<AudioResource> resourceReference)
@@ -278,11 +275,16 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		internal void RemoveResourceReference(WeakReference<AudioResource> resourceReference)
+		internal void RemoveResourceReference(AudioResource resource, WeakReference<AudioResource> resourceReference)
 		{
 			lock (StateLock)
 			{
 				resources.Remove(resourceReference);
+
+				if (resource is StreamingSound streamingSound)
+				{
+					RemoveDynamicSoundInstance(streamingSound);
+				}
 			}
 		}
 
@@ -314,7 +316,6 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		// TODO: override finalizer only if 'Dispose(bool disposing)' has code to free unmanaged resources
 		~AudioDevice()
 		{
 			// Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method

src/Audio/AudioResource.cs

@@ -28,7 +28,7 @@ namespace MoonWorks.Audio
 
 				if (selfReference != null)
 				{
-					Device.RemoveResourceReference(selfReference);
+					Device.RemoveResourceReference(this, selfReference);
 					selfReference = null;
 				}
 

src/Audio/StreamingSound.cs

@@ -91,6 +91,8 @@ namespace MoonWorks.Audio
 		internal unsafe void Update()
 		{
 			lock (StateLock)
+			{
+				if (!IsDisposed)
 				{
 					if (State != SoundState.Playing)
 					{
@@ -100,6 +102,7 @@ namespace MoonWorks.Audio
 					QueueBuffers();
 				}
 			}
+		}
 
 		protected void QueueBuffers()
 		{
@@ -181,6 +184,8 @@ namespace MoonWorks.Audio
 		protected unsafe override void Destroy()
 		{
 			lock (StateLock)
+			{
+				if (!IsDisposed)
 				{
 					StopImmediate();
 
@@ -192,3 +197,4 @@ namespace MoonWorks.Audio
 			}
 		}
 	}
+}

src/Audio/StreamingSoundOgg.cs

@@ -88,9 +88,14 @@ namespace MoonWorks.Audio
 		}
 
 		protected unsafe override void Destroy()
+		{
+			base.Destroy();
+
+			if (!IsDisposed)
 			{
 				FAudio.stb_vorbis_close(VorbisHandle);
 				NativeMemory.Free((void*) FileDataPtr);
 			}
 		}
 	}
+}

src/Video/StreamingSoundTheora.cs

@@ -32,6 +32,11 @@ namespace MoonWorks.Video
 		) {
 			var lengthInFloats = bufferLengthInBytes / sizeof(float);
 
+			// FIXME: this gets gnarly with theorafile being not thread safe
+			// is there some way we could just manually update in VideoPlayer
+			// instead of going through AudioDevice?
+			lock (Device.StateLock)
+			{
 				int samples = Theorafile.tf_readaudio(
 					VideoHandle,
 					(IntPtr) buffer,
@@ -41,6 +46,7 @@ namespace MoonWorks.Video
 				filledLengthInBytes = samples * sizeof(float);
 				reachedEnd = Theorafile.tf_eos(VideoHandle) == 1;
 			}
+		}
 
 		protected override void OnReachedEnd() { }
 	}

src/Video/Video.cs

@@ -27,7 +27,7 @@ namespace MoonWorks.Video
 		private int yWidth;
 		private int yHeight;
 
-		private bool disposed;
+		private bool IsDisposed;
 
 		public Video(string filename)
 		{
@@ -89,7 +89,7 @@ namespace MoonWorks.Video
 
 		protected virtual void Dispose(bool disposing)
 		{
-			if (!disposed)
+			if (!IsDisposed)
 			{
 				if (disposing)
 				{
@@ -100,7 +100,7 @@ namespace MoonWorks.Video
 				Theorafile.tf_close(ref Handle);
 				NativeMemory.Free(videoData);
 
-				disposed = true;
+				IsDisposed = true;
 			}
 		}
 

src/Video/VideoPlayer.cs

@@ -181,18 +181,22 @@ namespace MoonWorks.Video
 			lastTimestamp = 0;
 			timeElapsed = 0;
 
-			if (audioStream != null)
+			lock (AudioDevice.StateLock)
 			{
-				audioStream.StopImmediate();
+				DestroyAudioStream();
-				audioStream.Dispose();
-				audioStream = null;
-			}
 
 				Theorafile.tf_reset(Video.Handle);
+			}
 
 			State = VideoState.Stopped;
 		}
 
+		public void Unload()
+		{
+			Stop();
+			Video = null;
+		}
+
 		public void Render()
 		{
 			if (Video == null || State == VideoState.Stopped)
@@ -200,6 +204,9 @@ namespace MoonWorks.Video
 				return;
 			}
 
+			// Theorafile is not thread safe so we have to do this. Fun!
+			lock (AudioDevice.StateLock)
+			{
 				timeElapsed += (timer.Elapsed.TotalMilliseconds - lastTimestamp) * PlaybackSpeed;
 				lastTimestamp = timer.Elapsed.TotalMilliseconds;
 
@@ -210,7 +217,8 @@ namespace MoonWorks.Video
 						Video.Handle,
 						(IntPtr) yuvData,
 						thisFrame - currentFrame
-				) == 1 || currentFrame == -1) {
+					) == 1 || currentFrame == -1)
+					{
 						UpdateRenderTexture();
 					}
 
@@ -223,12 +231,7 @@ namespace MoonWorks.Video
 					timer.Stop();
 					timer.Reset();
 
-				if (audioStream != null)
+					DestroyAudioStream();
-				{
-					audioStream.Stop();
-					audioStream.Dispose();
-					audioStream = null;
-				}
 
 					Theorafile.tf_reset(Video.Handle);
 
@@ -245,6 +248,7 @@ namespace MoonWorks.Video
 					}
 				}
 			}
+		}
 
 		private void UpdateRenderTexture()
 		{
@@ -306,14 +310,27 @@ namespace MoonWorks.Video
 			// Grab the first bit of audio. We're trying to start the decoding ASAP.
 			if (AudioDevice != null && Theorafile.tf_hasaudio(Video.Handle) == 1)
 			{
+				DestroyAudioStream();
+
 				int channels, sampleRate;
 				Theorafile.tf_audioinfo(Video.Handle, out channels, out sampleRate);
+
 				audioStream = new StreamingSoundTheora(AudioDevice, Video.Handle, channels, (uint) sampleRate);
 			}
 
 			currentFrame = -1;
 		}
 
+		private void DestroyAudioStream()
+		{
+			if (audioStream != null)
+			{
+				audioStream.StopImmediate();
+				audioStream.Dispose();
+				audioStream = null;
+			}
+		}
+
 		protected virtual void Dispose(bool disposing)
 		{
 			if (!disposed)