Added ClearVoiceBuffer, thread support (disabled currently), and some minor voice performance improvements

src/Discord.Net/DiscordClient.cs

@@ -1328,6 +1328,12 @@ namespace Discord
 		{
 			_voiceWebSocket.SendPCMFrame(data, count);
 		}
+
+		/// <summary> Clears the PCM buffer. </summary>
+		public void ClearVoicePCM()
+		{
+			_voiceWebSocket.ClearPCMFrames();
+		}
 #endif
 
 		//Profile

src/Discord.Net/DiscordVoiceSocket.cs

@@ -1,4 +1,6 @@
-using Discord.API.Models;
+//#define USE_THREAD
+
+using Discord.API.Models;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 using System;
@@ -39,11 +41,14 @@ namespace Discord
 		private ConcurrentQueue<Packet> _sendQueue;
 		private UdpClient _udp;
 		private IPEndPoint _endpoint;
-		private bool _isReady;
+		private bool _isReady, _isClearing;
 		private byte[] _secretKey;
 		private string _myIp;
 		private ushort _sequence;
 		private string _mode;
+#if USE_THREAD
+		private Thread _sendThread;
+#endif
 #endif
 
 		public DiscordVoiceSocket(DiscordClient client, int timeout, int interval)
@@ -62,20 +67,31 @@ namespace Discord
 			_udp = new UdpClient(new IPEndPoint(IPAddress.Any, 0));
 			_udp.AllowNatTraversal(true);
 			_isReady = false;
+			_isClearing = false;
         }
 		protected override void OnDisconnect()
 		{
 			_udp = null;
-		}
+#if USE_THREAD
+			_sendThread.Join();
+			_sendThread = null;
+#endif
+        }
 #endif
 
 		protected override Task[] CreateTasks()
 		{
-            return new Task[]
+#if !DNXCORE50 && USE_THREAD
+			_sendThread = new Thread(new ThreadStart(() => SendAsync(_disconnectToken)));
+			_sendThread.Start();
+#endif
+			return new Task[]
 			{
 #if !DNXCORE50
 				ReceiveAsync(),
+#if !USE_THREAD
 				SendAsync(),
+#endif
 #endif
 				WatcherAsync()
 			}.Concat(base.CreateTasks()).ToArray();
@@ -110,73 +126,109 @@ namespace Discord
 #if !DNXCORE50
 		private async Task ReceiveAsync()
 		{
-			var cancelToken = _disconnectToken.Token;
+			var cancelSource = _disconnectToken;
+			var cancelToken = cancelSource.Token;
+			await Task.Yield();
+
 			try
 			{
 				while (!cancelToken.IsCancellationRequested)
 				{
-					var result = await _udp.ReceiveAsync();					
+					var result = await _udp.ReceiveAsync();
 					ProcessUdpMessage(result);
 				}
 			}
 			catch { }
-			finally { _disconnectToken.Cancel(); }
+			finally { cancelSource.Cancel(); }
 		}
+
+#if USE_THREAD
+		private void SendAsync(CancellationTokenSource cancelSource)
+		{
+			var cancelToken = cancelSource.Token;
+#else
 		private async Task SendAsync()
 		{
-			var cancelToken = _disconnectToken.Token;
+			var cancelSource = _disconnectToken;
+			var cancelToken = cancelSource.Token;
+			await Task.Yield();
+#endif
+
 			Packet packet;
 			try
 			{
+				while (!cancelToken.IsCancellationRequested && !_isReady)
+					Thread.Sleep(1);
+
+				if (cancelToken.IsCancellationRequested)
+					return;
+
 				uint timestamp = 0;
 				double nextTicks = 0.0;
-				double ticksPerFrame = Stopwatch.Frequency / 1000.0 * _encoder.FrameLength;
+				double ticksPerMillisecond = Stopwatch.Frequency / 1000.0;
+                double ticksPerFrame = ticksPerMillisecond * _encoder.FrameLength;
+				double spinLockThreshold = 1.5 * ticksPerMillisecond;
 				uint samplesPerFrame = (uint)_encoder.SamplesPerFrame;
 				Stopwatch sw = Stopwatch.StartNew();
+
+				byte[] rtpPacket = new byte[4012];
+				rtpPacket[0] = 0x80; //Flags;
+				rtpPacket[1] = 0x78; //Payload Type
+				rtpPacket[8] = (byte)((_ssrc >> 24) & 0xFF);
+				rtpPacket[9] = (byte)((_ssrc >> 16) & 0xFF);
+				rtpPacket[10] = (byte)((_ssrc >> 8) & 0xFF);
+				rtpPacket[11] = (byte)((_ssrc >> 0) & 0xFF);
+
 				while (!cancelToken.IsCancellationRequested)
 				{
-					byte[] rtpPacket = new byte[4012];
-					rtpPacket[0] = 0x80; //Flags;
-					rtpPacket[1] = 0x78; //Payload Type
-					rtpPacket[8] = (byte)((_ssrc >> 24) & 0xFF);
-					rtpPacket[9] = (byte)((_ssrc >> 16) & 0xFF);
-					rtpPacket[10] = (byte)((_ssrc >> 8) & 0xFF);
-					rtpPacket[11] = (byte)((_ssrc >> 0) & 0xFF);
-
-                    if (_isReady && sw.ElapsedTicks > nextTicks)
+					double ticksToNextFrame = nextTicks - sw.ElapsedTicks;
+					if (ticksToNextFrame <= 0.0)
 					{
 						while (sw.ElapsedTicks > nextTicks)
 						{
-							if (_sendQueue.TryDequeue(out packet))
+							if (!_isClearing)
 							{
-								ushort sequence = unchecked(_sequence++);
-								rtpPacket[2] = (byte)((sequence >> 8) & 0xFF);
-								rtpPacket[3] = (byte)((sequence >> 0) & 0xFF);
-								rtpPacket[4] = (byte)((timestamp >> 24) & 0xFF);
-								rtpPacket[5] = (byte)((timestamp >> 16) & 0xFF);
-								rtpPacket[6] = (byte)((timestamp >> 8) & 0xFF);
-								rtpPacket[7] = (byte)((timestamp >> 0) & 0xFF);
-								Buffer.BlockCopy(packet.Data, 0, rtpPacket, 12, packet.Count);
-								await _udp.SendAsync(rtpPacket, packet.Count + 12);
+								if (_sendQueue.TryDequeue(out packet))
+								{
+									ushort sequence = unchecked(_sequence++);
+									rtpPacket[2] = (byte)((sequence >> 8) & 0xFF);
+									rtpPacket[3] = (byte)((sequence >> 0) & 0xFF);
+									rtpPacket[4] = (byte)((timestamp >> 24) & 0xFF);
+									rtpPacket[5] = (byte)((timestamp >> 16) & 0xFF);
+									rtpPacket[6] = (byte)((timestamp >> 8) & 0xFF);
+									rtpPacket[7] = (byte)((timestamp >> 0) & 0xFF);
+									Buffer.BlockCopy(packet.Data, 0, rtpPacket, 12, packet.Count);
+#if USE_THREAD
+									_udp.Send(rtpPacket, packet.Count + 12);
+#else
+									await _udp.SendAsync(rtpPacket, packet.Count + 12);
+#endif
+								}
+								timestamp = unchecked(timestamp + samplesPerFrame);
+								nextTicks += ticksPerFrame;
 							}
-							timestamp = unchecked(timestamp + samplesPerFrame);
-							nextTicks += ticksPerFrame;
 						}
 					}
-					else
+					//Dont sleep for 1 millisecond if we need to output audio in the next 1.5
+					else if (_sendQueue.Count == 0 || ticksToNextFrame >= spinLockThreshold)
+#if USE_THREAD
+						Thread.Sleep(1);
+#else
 						await Task.Delay(1);
+#endif
 				}
 			}
 			catch { }
-			finally { _disconnectToken.Cancel(); }
+			finally { cancelSource.Cancel(); }
 		}
 #endif
-		//Closes the UDP socket when _disconnectToken is triggered, since UDPClient doesn't allow passing a canceltoken
+					//Closes the UDP socket when _disconnectToken is triggered, since UDPClient doesn't allow passing a canceltoken
 		private async Task WatcherAsync()
 		{
+			var cancelToken = _disconnectToken.Token;
 			try
 			{
-				await Task.Delay(-1, _disconnectToken.Token);
+				await Task.Delay(-1, cancelToken);
 			}
 			catch (TaskCanceledException) { }
 #if !DNXCORE50
@@ -210,7 +262,7 @@ namespace Discord
 
 							_sequence = (ushort)_rand.Next(0, ushort.MaxValue);
 							//No thread issue here because SendAsync doesn't start until _isReady is true
-							_udp.Send(new byte[70] {
+							await _udp.SendAsync(new byte[70] {
 								(byte)((_ssrc >> 24) & 0xFF),
 								(byte)((_ssrc >> 16) & 0xFF),
 								(byte)((_ssrc >> 8) & 0xFF),
@@ -322,16 +374,26 @@ namespace Discord
 			if (count != _encoder.FrameSize)
 				throw new InvalidOperationException($"Invalid frame size. Got {count}, expected {_encoder.FrameSize}.");
 
-			byte[] payload = new byte[4000];
-			int encodedLength = _encoder.EncodeFrame(data, payload);
-
-			if (_mode == "xsalsa20_poly1305")
+			lock (_encoder)
 			{
-				//TODO: Encode
+				byte[] payload = new byte[4000];
+				int encodedLength = _encoder.EncodeFrame(data, payload);
+
+				if (_mode == "xsalsa20_poly1305")
+				{
+					//TODO: Encode
+				}
+
+				lock (_sendQueue)
+					_sendQueue.Enqueue(new Packet(payload, encodedLength));
 			}
-			
-			lock (_sendQueue)
-				_sendQueue.Enqueue(new Packet(payload, encodedLength));
+		}
+		public void ClearPCMFrames()
+		{
+			_isClearing = true;
+			Packet ignored;
+            while (_sendQueue.TryDequeue(out ignored)) { }
+			_isClearing = false;
 		}
 
 		private void SendIsTalking(bool value)

src/Discord.Net/DiscordWebSocket.cs

@@ -55,20 +55,20 @@ namespace Discord
 			_lastHeartbeat = DateTime.UtcNow;
 			_tasks = Task.Factory.ContinueWhenAll(CreateTasks(), x =>
 			{
-				//Do not clean up until both tasks have ended
-				_heartbeatInterval = 0;
-				_lastHeartbeat = DateTime.MinValue;
-				_webSocket.Dispose();
-				_webSocket = null;
+				//Do not clean up until all tasks have ended
+				OnDisconnect();
+
 				_disconnectToken.Dispose();
 				_disconnectToken = null;
 
 				//Clear send queue
+				_heartbeatInterval = 0;
+				_lastHeartbeat = DateTime.MinValue;
+				_webSocket.Dispose();
+				_webSocket = null;
 				byte[] ignored;
 				while (_sendQueue.TryDequeue(out ignored)) { }
 
-				OnDisconnect();
-
 				if (_isConnected)
 				{
 					_isConnected = false;
@@ -106,7 +106,10 @@ namespace Discord
 
 		private async Task ReceiveAsync()
 		{
-			var cancelToken = _disconnectToken.Token;
+			var cancelSource = _disconnectToken;
+			var cancelToken = cancelSource.Token;
+			await Task.Yield();
+
 			var buffer = new byte[ReceiveChunkSize];
 			var builder = new StringBuilder();
 
@@ -117,7 +120,7 @@ namespace Discord
 					WebSocketReceiveResult result;
 					do
 					{
-						result = await _webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), _disconnectToken.Token);
+						result = await _webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), cancelToken);
 
 						if (result.MessageType == WebSocketMessageType.Close)
 						{
@@ -139,11 +142,14 @@ namespace Discord
 				}
 			}
 			catch { }
-			finally { _disconnectToken.Cancel(); }
+			finally { cancelSource.Cancel(); }
 		}
 		private async Task SendAsync()
 		{
-			var cancelToken = _disconnectToken.Token;
+			var cancelSource = _disconnectToken;
+			var cancelToken = cancelSource.Token;
+			await Task.Yield();
+
 			try
 			{
 				byte[] bytes;
@@ -164,7 +170,7 @@ namespace Discord
 				}
 			}
 			catch { }
-			finally { _disconnectToken.Cancel(); }
+			finally { cancelSource.Cancel(); }
 		}
 
 		protected abstract Task ProcessMessage(string json);