fix: WebSocketException on manual reconnection after manual disconnection

Author: doghappy

src/SocketIOClient.Windows7/ClientWebSocketManaged.cs

@@ -11,33 +11,43 @@ public sealed class ClientWebSocketManaged : IClientWebSocket
         public ClientWebSocketManaged()
         {
             _ws = new System.Net.WebSockets.Managed.ClientWebSocket();
+            _sendLock = new SemaphoreSlim(1, 1);
         }
 
         readonly System.Net.WebSockets.Managed.ClientWebSocket _ws;
+        readonly SemaphoreSlim _sendLock;
 
         public Action<object> ConfigOptions { get; set; }
 
         public WebSocketState State => _ws.State;
 
         public async Task CloseAsync(WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
         {
-            await _ws.CloseAsync(closeStatus, statusDescription, cancellationToken);
+            await _ws.CloseAsync(closeStatus, statusDescription, cancellationToken).ConfigureAwait(false);
         }
 
         public async Task ConnectAsync(Uri uri, CancellationToken cancellationToken)
         {
             ConfigOptions?.Invoke(_ws.Options);
-            await _ws.ConnectAsync(uri, cancellationToken);
+            await _ws.ConnectAsync(uri, cancellationToken).ConfigureAwait(false);
         }
 
         public async Task<WebSocketReceiveResult> ReceiveAsync(ArraySegment<byte> buffer, CancellationToken cancellationToken)
         {
-            return await _ws.ReceiveAsync(buffer, cancellationToken);
+            return await _ws.ReceiveAsync(buffer, cancellationToken).ConfigureAwait(false);
         }
 
         public async Task SendAsync(ArraySegment<byte> buffer, WebSocketMessageType messageType, bool endOfMessage, CancellationToken cancellationToken)
         {
-            await _ws.SendAsync(buffer, messageType, endOfMessage, cancellationToken);
+            try
+            {
+                await _sendLock.WaitAsync().ConfigureAwait(false);
+                await _ws.SendAsync(buffer, messageType, endOfMessage, cancellationToken).ConfigureAwait(false);
+            }
+            finally
+            {
+                _sendLock.Release();
+            }
         }
 
         public void Dispose()

src/SocketIOClient/Transport/DefaultClientWebSocket.cs

@@ -10,33 +10,43 @@ public class DefaultClientWebSocket : IClientWebSocket
         public DefaultClientWebSocket()
         {
             _ws = new ClientWebSocket();
+            _sendLock = new SemaphoreSlim(1, 1);
         }
 
         readonly ClientWebSocket _ws;
+        readonly SemaphoreSlim _sendLock;
 
         public Action<object> ConfigOptions { get; set; }
 
         public WebSocketState State => _ws.State;
 
         public async Task CloseAsync(WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
         {
-            await _ws.CloseAsync(closeStatus, statusDescription, cancellationToken);
+            await _ws.CloseAsync(closeStatus, statusDescription, cancellationToken).ConfigureAwait(false);
         }
 
         public async Task ConnectAsync(Uri uri, CancellationToken cancellationToken)
         {
             ConfigOptions?.Invoke(_ws.Options);
-            await _ws.ConnectAsync(uri, cancellationToken);
+            await _ws.ConnectAsync(uri, cancellationToken).ConfigureAwait(false);
         }
 
         public async Task<WebSocketReceiveResult> ReceiveAsync(ArraySegment<byte> buffer, CancellationToken cancellationToken)
         {
-            return await _ws.ReceiveAsync(buffer, cancellationToken);
+            return await _ws.ReceiveAsync(buffer, cancellationToken).ConfigureAwait(false);
         }
 
         public async Task SendAsync(ArraySegment<byte> buffer, WebSocketMessageType messageType, bool endOfMessage, CancellationToken cancellationToken)
         {
-            await _ws.SendAsync(buffer, messageType, endOfMessage, cancellationToken);
+            try
+            {
+                await _sendLock.WaitAsync().ConfigureAwait(false);
+                await _ws.SendAsync(buffer, messageType, endOfMessage, cancellationToken).ConfigureAwait(false);
+            }
+            finally
+            {
+                _sendLock.Release();
+            }
         }
 
         public void Dispose()

src/SocketIOClient/Transport/TransportRouter.cs

@@ -134,13 +134,13 @@ private void StartPolling()
             }, TaskCreationOptions.LongRunning);
         }
 
-        private void OnWebSocketTextReceived(string text)
+        private async void OnWebSocketTextReceived(string text)
         {
             if (text == "3probe")
             {
                 var msg = new ConnectedMessage { Namespace = Namespace, Sid = Sid };
-                _ = _webSocketTransport.SendAsync("5", CancellationToken.None);
-                _ = _webSocketTransport.SendAsync(msg.Write(), CancellationToken.None);
+                await _webSocketTransport.SendAsync("5", CancellationToken.None);
+                await _webSocketTransport.SendAsync(msg.Write(), CancellationToken.None);
             }
             else
             {