feature: Implement Dispose for types which have disposable data (#1171)

* Initial set of dispose implementations

Not handled yet:
- Discord.Net.Websocket/Entities/SocketGuild
- Discord.Net.Tests

* Refactor DiscordSocketClient init into ctor

This way we remove an IDisposableAnalyzer warning for not disposing
the client when we set the client variable.

* Dispose of clients when disposing sharded client

* Finish implementing IDisposable where appropriate

I opted to use NoWarn in the Tests project as it wasn't really necessary
considering that our tests only run once

* Tweak samples after feedback

src/Discord.Net.WebSocket/Audio/AudioClient.cs

@@ -71,7 +71,7 @@ namespace Discord.Audio
             ApiClient.ReceivedPacket += ProcessPacketAsync;
 
             _stateLock = new SemaphoreSlim(1, 1);
-            _connection = new ConnectionManager(_stateLock, _audioLogger, 30000, 
+            _connection = new ConnectionManager(_stateLock, _audioLogger, 30000,
                 OnConnectingAsync, OnDisconnectingAsync, x => ApiClient.Disconnected += x);
             _connection.Connected += () => _connectedEvent.InvokeAsync();
             _connection.Disconnected += (ex, recon) => _disconnectedEvent.InvokeAsync(ex);
@@ -79,7 +79,7 @@ namespace Discord.Audio
             _keepaliveTimes = new ConcurrentQueue<KeyValuePair<ulong, int>>();
             _ssrcMap = new ConcurrentDictionary<uint, ulong>();
             _streams = new ConcurrentDictionary<ulong, StreamPair>();
-            
+
             _serializer = new JsonSerializer { ContractResolver = new DiscordContractResolver() };
             _serializer.Error += (s, e) =>
             {
@@ -91,7 +91,7 @@ namespace Discord.Audio
             UdpLatencyUpdated += async (old, val) => await _audioLogger.DebugAsync($"UDP Latency = {val} ms").ConfigureAwait(false);
         }
 
-        internal async Task StartAsync(string url, ulong userId, string sessionId, string token) 
+        internal async Task StartAsync(string url, ulong userId, string sessionId, string token)
         {
             _url = url;
             _userId = userId;
@@ -100,7 +100,7 @@ namespace Discord.Audio
             await _connection.StartAsync().ConfigureAwait(false);
         }
         public async Task StopAsync()
-        { 
+        {
             await _connection.StopAsync().ConfigureAwait(false);
         }
 
@@ -225,11 +225,11 @@ namespace Discord.Audio
 
                             if (!data.Modes.Contains(DiscordVoiceAPIClient.Mode))
                                 throw new InvalidOperationException($"Discord does not support {DiscordVoiceAPIClient.Mode}");
-                            
+
                             ApiClient.SetUdpEndpoint(data.Ip, data.Port);
                             await ApiClient.SendDiscoveryAsync(_ssrc).ConfigureAwait(false);
 
-                            
+
                             _heartbeatTask = RunHeartbeatAsync(41250, _connection.CancelToken);
                         }
                         break;
@@ -305,9 +305,9 @@ namespace Discord.Audio
                     catch (Exception ex)
                     {
                         await _audioLogger.DebugAsync("Malformed Packet", ex).ConfigureAwait(false);
-                        return; 
+                        return;
                     }
-                    
+
                     await _audioLogger.DebugAsync("Received Discovery").ConfigureAwait(false);
                     await ApiClient.SendSelectProtocol(ip, port).ConfigureAwait(false);
                 }
@@ -317,7 +317,7 @@ namespace Discord.Audio
                     {
                         await _audioLogger.DebugAsync("Received Keepalive").ConfigureAwait(false);
 
-                        ulong value = 
+                        ulong value =
                             ((ulong)packet[0] >> 0) |
                             ((ulong)packet[1] >> 8) |
                             ((ulong)packet[2] >> 16) |
@@ -341,7 +341,7 @@ namespace Discord.Audio
                         }
                     }
                     else
-                    {                        
+                    {
                         if (!RTPReadStream.TryReadSsrc(packet, 0, out var ssrc))
                         {
                             await _audioLogger.DebugAsync("Malformed Frame").ConfigureAwait(false);
@@ -388,7 +388,7 @@ namespace Discord.Audio
                     var now = Environment.TickCount;
 
                     //Did server respond to our last heartbeat?
-                    if (_heartbeatTimes.Count != 0 && (now - _lastMessageTime) > intervalMillis && 
+                    if (_heartbeatTimes.Count != 0 && (now - _lastMessageTime) > intervalMillis &&
                         ConnectionState == ConnectionState.Connected)
                     {
                         _connection.Error(new Exception("Server missed last heartbeat"));
@@ -437,7 +437,7 @@ namespace Discord.Audio
                     {
                         await _audioLogger.WarningAsync("Failed to send keepalive", ex).ConfigureAwait(false);
                     }
-                    
+
                     await Task.Delay(intervalMillis, cancelToken).ConfigureAwait(false);
                 }
                 await _audioLogger.DebugAsync("Keepalive Stopped").ConfigureAwait(false);
@@ -467,6 +467,7 @@ namespace Discord.Audio
             {
                 StopAsync().GetAwaiter().GetResult();
                 ApiClient.Dispose();
+                _stateLock?.Dispose();
             }
         }
         /// <inheritdoc />

src/Discord.Net.WebSocket/Audio/Streams/BufferedWriteStream.cs

@@ -27,7 +27,7 @@ namespace Discord.Audio.Streams
 
         private readonly AudioClient _client;
         private readonly AudioStream _next;
-        private readonly CancellationTokenSource _cancelTokenSource;
+        private readonly CancellationTokenSource _disposeTokenSource, _cancelTokenSource;
         private readonly CancellationToken _cancelToken;
         private readonly Task _task;
         private readonly ConcurrentQueue<Frame> _queuedFrames;
@@ -49,12 +49,13 @@ namespace Discord.Audio.Streams
             _logger = logger;
             _queueLength = (bufferMillis + (_ticksPerFrame - 1)) / _ticksPerFrame; //Round up
 
-            _cancelTokenSource = new CancellationTokenSource();
-            _cancelToken = CancellationTokenSource.CreateLinkedTokenSource(_cancelTokenSource.Token, cancelToken).Token;
+            _disposeTokenSource = new CancellationTokenSource();
+            _cancelTokenSource = CancellationTokenSource.CreateLinkedTokenSource(_disposeTokenSource.Token, cancelToken);
+            _cancelToken = _cancelTokenSource.Token;
             _queuedFrames = new ConcurrentQueue<Frame>();
             _bufferPool = new ConcurrentQueue<byte[]>();
             for (int i = 0; i < _queueLength; i++)
-                _bufferPool.Enqueue(new byte[maxFrameSize]); 
+                _bufferPool.Enqueue(new byte[maxFrameSize]);
             _queueLock = new SemaphoreSlim(_queueLength, _queueLength);
             _silenceFrames = MaxSilenceFrames;
 
@@ -63,7 +64,12 @@ namespace Discord.Audio.Streams
         protected override void Dispose(bool disposing)
         {
             if (disposing)
-                _cancelTokenSource.Cancel();
+            {
+                _disposeTokenSource?.Cancel();
+                _disposeTokenSource?.Dispose();
+                _cancelTokenSource?.Dispose();
+                _queueLock?.Dispose();
+            }
             base.Dispose(disposing);
         }
 
@@ -131,8 +137,12 @@ namespace Discord.Audio.Streams
         public override void WriteHeader(ushort seq, uint timestamp, bool missed) { } //Ignore, we use our own timing
         public override async Task WriteAsync(byte[] data, int offset, int count, CancellationToken cancelToken)
         {
+            CancellationTokenSource writeCancelToken = null;
             if (cancelToken.CanBeCanceled)
-                cancelToken = CancellationTokenSource.CreateLinkedTokenSource(cancelToken, _cancelToken).Token;
+            {
+                writeCancelToken = CancellationTokenSource.CreateLinkedTokenSource(cancelToken, _cancelToken);
+                cancelToken = writeCancelToken.Token;
+            }
             else
                 cancelToken = _cancelToken;
 
@@ -142,6 +152,9 @@ namespace Discord.Audio.Streams
 #if DEBUG
                 var _ = _logger?.DebugAsync("Buffer overflow"); //Should never happen because of the queueLock
 #endif
+#pragma warning disable IDISP016
+                writeCancelToken?.Dispose();
+#pragma warning restore IDISP016
                 return;
             }
             Buffer.BlockCopy(data, offset, buffer, 0, count);
@@ -153,6 +166,7 @@ namespace Discord.Audio.Streams
 #endif
                 _isPreloaded = true;
             }
+            writeCancelToken?.Dispose();
         }
 
         public override async Task FlushAsync(CancellationToken cancelToken)

src/Discord.Net.WebSocket/Audio/Streams/InputStream.cs

@@ -96,7 +96,17 @@ namespace Discord.Audio.Streams
 
         protected override void Dispose(bool isDisposing)
         {
-            _isDisposed = true;
+            if (!_isDisposed)
+            {
+                if (isDisposing)
+                {
+                    _signal?.Dispose();
+                }
+
+                _isDisposed = true;
+            }
+
+            base.Dispose(isDisposing);
         }
     }
 }