Fixes "InvalidOperationException" errors by performing async operations in SemaphoreSlim

src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj

@@ -442,6 +442,7 @@
     <Compile Include="Microsoft\Data\SqlClient\SNI\SNIPhysicalHandle.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SNI\SNIProxy.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SNI\SNITcpHandle.cs" />
+    <Compile Include="Microsoft\Data\SqlClient\SNI\SNIStreams.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SNI\SslOverTdsStream.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SNI\SNICommon.cs" />
     <Compile Include="Microsoft\Data\SqlClient\SNI\SspiClientContextStatus.cs" />

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SNI/SNINpHandle.cs

@@ -93,7 +93,7 @@ public SNINpHandle(string serverName, string pipeName, long timerExpire, object
                 }
 
                 _sslOverTdsStream = new SslOverTdsStream(_pipeStream);
-                _sslStream = new SslStream(_sslOverTdsStream, true, new RemoteCertificateValidationCallback(ValidateServerCertificate), null);
+                _sslStream = new SNISslStream(_sslOverTdsStream, true, new RemoteCertificateValidationCallback(ValidateServerCertificate));
 
                 _stream = _pipeStream;
                 _status = TdsEnums.SNI_SUCCESS;
@@ -286,7 +286,7 @@ public override uint Send(SNIPacket packet)
                     }
 
                     // this lock ensures that two packets are not being written to the transport at the same time
-                    // so that sending a standard and an out-of-band packet are both written atomically no data is 
+                    // so that sending a standard and an out-of-band packet are both written atomically no data is
                     // interleaved
                     lock (_sendSync)
                     {

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SNI/SNIStreams.cs

@@ -0,0 +1,99 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Net.Security;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Net.Sockets;
+
+namespace Microsoft.Data.SqlClient.SNI
+{
+    /// <summary>
+    /// This class extends SslStream to customize stream behavior for Managed SNI implementation.
+    /// </summary>
+    internal class SNISslStream : SslStream
+    {
+        private readonly SemaphoreSlim _writeAsyncSemaphore;
+        private readonly SemaphoreSlim _readAsyncSemaphore;
+
+        public SNISslStream(Stream innerStream, bool leaveInnerStreamOpen, RemoteCertificateValidationCallback userCertificateValidationCallback)
+            : base(innerStream, leaveInnerStreamOpen, userCertificateValidationCallback)
+        {
+            _writeAsyncSemaphore = new SemaphoreSlim(1);
+            _readAsyncSemaphore = new SemaphoreSlim(1);
+        }
+
+        // Prevent ReadAsync collisions by running the task in a Semaphore Slim
+        public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            await _readAsyncSemaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                return await base.ReadAsync(buffer, offset, count, cancellationToken);
+            }
+            finally
+            {
+                _readAsyncSemaphore.Release();
+            }
+        }
+
+        // Prevent the WriteAsync collisions by running the task in a Semaphore Slim
+        public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            await _writeAsyncSemaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                await base.WriteAsync(buffer, offset, count, cancellationToken);
+            }
+            finally
+            {
+                _writeAsyncSemaphore.Release();
+            }
+        }
+    }
+
+    /// <summary>
+    /// This class extends NetworkStream to customize stream behavior for Managed SNI implementation.
+    /// </summary>
+    internal class SNINetworkStream : NetworkStream
+    {
+        private readonly SemaphoreSlim _writeAsyncSemaphore;
+        private readonly SemaphoreSlim _readAsyncSemaphore;
+
+        public SNINetworkStream(Socket socket, bool ownsSocket) : base(socket, ownsSocket)
+        {
+            _writeAsyncSemaphore = new SemaphoreSlim(1);
+            _readAsyncSemaphore = new SemaphoreSlim(1);
+        }
+
+        // Prevent the ReadAsync collisions by running the task in a Semaphore Slim
+        public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            await _readAsyncSemaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                return await base.ReadAsync(buffer, offset, count, cancellationToken);
+            }
+            finally
+            {
+                _readAsyncSemaphore.Release();
+            }
+        }
+
+        // Prevent the WriteAsync collisions by running the task in a Semaphore Slim
+        public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            await _writeAsyncSemaphore.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                await base.WriteAsync(buffer, offset, count, cancellationToken);
+            }
+            finally
+            {
+                _writeAsyncSemaphore.Release();
+            }
+        }
+    }
+}

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SNI/SNITcpHandle.cs

@@ -143,7 +143,7 @@ public SNITCPHandle(string serverName, int port, long timerExpire, object callba
                 bool reportError = true;
 
                 // We will always first try to connect with serverName as before and let the DNS server to resolve the serverName.
-                // If the DSN resolution fails, we will try with IPs in the DNS cache if existed. We try with IPv4 first and followed by IPv6 if 
+                // If the DSN resolution fails, we will try with IPs in the DNS cache if existed. We try with IPv4 first and followed by IPv6 if
                 // IPv4 fails. The exceptions will be throw to upper level and be handled as before.
                 try
                 {
@@ -160,14 +160,14 @@ public SNITCPHandle(string serverName, int port, long timerExpire, object callba
                 {
                     // Retry with cached IP address
                     if (ex is SocketException || ex is ArgumentException || ex is AggregateException)
-                    {                       
+                    {
                         if (hasCachedDNSInfo == false)
                         {
                             throw;
                         }
                         else
                         {
-                            int portRetry = String.IsNullOrEmpty(cachedDNSInfo.Port) ? port : Int32.Parse(cachedDNSInfo.Port); 
+                            int portRetry = String.IsNullOrEmpty(cachedDNSInfo.Port) ? port : Int32.Parse(cachedDNSInfo.Port);
 
                             try
                             {
@@ -180,9 +180,9 @@ public SNITCPHandle(string serverName, int port, long timerExpire, object callba
                                     _socket = Connect(cachedDNSInfo.AddrIPv4, portRetry, ts, isInfiniteTimeOut, cachedFQDN, ref pendingDNSInfo);
                                 }
                             }
-                            catch(Exception exRetry)
+                            catch (Exception exRetry)
                             {
-                                if (exRetry is SocketException || exRetry is ArgumentNullException 
+                                if (exRetry is SocketException || exRetry is ArgumentNullException
                                     || exRetry is ArgumentException || exRetry is ArgumentOutOfRangeException || exRetry is AggregateException)
                                 {
                                     if (parallel)
@@ -199,7 +199,7 @@ public SNITCPHandle(string serverName, int port, long timerExpire, object callba
                                     throw;
                                 }
                             }
-                        }                        
+                        }
                     }
                     else
                     {
@@ -223,10 +223,10 @@ public SNITCPHandle(string serverName, int port, long timerExpire, object callba
                 }
 
                 _socket.NoDelay = true;
-                _tcpStream = new NetworkStream(_socket, true);
+                _tcpStream = new SNINetworkStream(_socket, true);
 
                 _sslOverTdsStream = new SslOverTdsStream(_tcpStream);
-                _sslStream = new SslStream(_sslOverTdsStream, true, new RemoteCertificateValidationCallback(ValidateServerCertificate), null);
+                _sslStream = new SNISslStream(_sslOverTdsStream, true, new RemoteCertificateValidationCallback(ValidateServerCertificate));
             }
             catch (SocketException se)
             {
@@ -331,7 +331,7 @@ private static Socket Connect(string serverName, int port, TimeSpan timeout, boo
             }
 
             CancellationTokenSource cts = null;
-            
+
             void Cancel()
             {
                 for (int i = 0; i < sockets.Length; ++i)
@@ -355,7 +355,7 @@ void Cancel()
             }
 
             Socket availableSocket = null;
-            try 
+            try
             {
                 for (int i = 0; i < sockets.Length; ++i)
                 {
@@ -566,45 +566,45 @@ public override uint Send(SNIPacket packet)
         {
             bool releaseLock = false;
             try
-            {
-                // is the packet is marked out out-of-band (attention packets only) it must be
-                // sent immediately even if a send of recieve operation is already in progress
-                // because out of band packets are used to cancel ongoing operations
-                // so try to take the lock if possible but continue even if it can't be taken
-                if (packet.IsOutOfBand)
-                {
-                    Monitor.TryEnter(this, ref releaseLock);
-                }
-                else
-                {
-                    Monitor.Enter(this);
-                    releaseLock = true;
-                }
-
-                // this lock ensures that two packets are not being written to the transport at the same time
-                // so that sending a standard and an out-of-band packet are both written atomically no data is 
-                // interleaved
-                lock (_sendSync)
                 {
-                    try
-                    {
-                        packet.WriteToStream(_stream);
-                        return TdsEnums.SNI_SUCCESS;
-                    }
-                    catch (ObjectDisposedException ode)
+                    // is the packet is marked out out-of-band (attention packets only) it must be
+                    // sent immediately even if a send of recieve operation is already in progress
+                    // because out of band packets are used to cancel ongoing operations
+                    // so try to take the lock if possible but continue even if it can't be taken
+                    if (packet.IsOutOfBand)
                     {
-                        return ReportTcpSNIError(ode);
+                        Monitor.TryEnter(this, ref releaseLock);
                     }
-                    catch (SocketException se)
+                    else
                     {
-                        return ReportTcpSNIError(se);
+                        Monitor.Enter(this);
+                        releaseLock = true;
                     }
-                    catch (IOException ioe)
+
+                    // this lock ensures that two packets are not being written to the transport at the same time
+                    // so that sending a standard and an out-of-band packet are both written atomically no data is
+                    // interleaved
+                    lock (_sendSync)
                     {
-                        return ReportTcpSNIError(ioe);
+                        try
+                        {
+                            packet.WriteToStream(_stream);
+                            return TdsEnums.SNI_SUCCESS;
+                        }
+                        catch (ObjectDisposedException ode)
+                        {
+                            return ReportTcpSNIError(ode);
+                        }
+                        catch (SocketException se)
+                        {
+                            return ReportTcpSNIError(se);
+                        }
+                        catch (IOException ioe)
+                        {
+                            return ReportTcpSNIError(ioe);
+                        }
                     }
                 }
-            }
             finally
             {
                 if (releaseLock)
@@ -633,7 +633,8 @@ public override uint Receive(out SNIPacket packet, int timeoutInMilliseconds)
                         _socket.ReceiveTimeout = timeoutInMilliseconds;
                     }
                     else if (timeoutInMilliseconds == -1)
-                    {   // SqlCient internally represents infinite timeout by -1, and for TcpClient this is translated to a timeout of 0 
+                    {
+                        // SqlClient internally represents infinite timeout by -1, and for TcpClient this is translated to a timeout of 0
                         _socket.ReceiveTimeout = 0;
                     }
                     else
@@ -706,12 +707,17 @@ public override void SetAsyncCallbacks(SNIAsyncCallback receiveCallback, SNIAsyn
         /// <returns>SNI error code</returns>
         public override uint SendAsync(SNIPacket packet, SNIAsyncCallback callback = null)
         {
-            SNIAsyncCallback cb = callback ?? _sendCallback;
-            lock (this)
+            long scopeID = SqlClientEventSource.Log.TrySNIScopeEnterEvent("<sc.SNI.SNIMarsHandle.SendAsync |SNI|INFO|SCOPE>");
+            try
             {
+                SNIAsyncCallback cb = callback ?? _sendCallback;
                 packet.WriteToStreamAsync(_stream, cb, SNIProviders.TCP_PROV);
+                return TdsEnums.SNI_SUCCESS_IO_PENDING;
+            }
+            finally
+            {
+                SqlClientEventSource.Log.TrySNIScopeLeaveEvent(scopeID);
             }
-            return TdsEnums.SNI_SUCCESS_IO_PENDING;
         }
 
         /// <summary>
@@ -745,15 +751,15 @@ public override uint CheckConnection()
         {
             try
             {
-                // _socket.Poll method with argument SelectMode.SelectRead returns 
+                // _socket.Poll method with argument SelectMode.SelectRead returns
                 //      True : if Listen has been called and a connection is pending, or
                 //      True : if data is available for reading, or
                 //      True : if the connection has been closed, reset, or terminated, i.e no active connection.
                 //      False : otherwise.
                 // _socket.Available property returns the number of bytes of data available to read.
                 //
-                // Since _socket.Connected alone doesn't guarantee if the connection is still active, we use it in 
-                // combination with _socket.Poll method and _socket.Available == 0 check. When both of them 
+                // Since _socket.Connected alone doesn't guarantee if the connection is still active, we use it in
+                // combination with _socket.Poll method and _socket.Available == 0 check. When both of them
                 // return true we can safely determine that the connection is no longer active.
                 if (!_socket.Connected || (_socket.Poll(100, SelectMode.SelectRead) && _socket.Available == 0))
                 {

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SNI/SslOverTdsStream.NetCoreApp.cs

@@ -12,24 +12,16 @@ namespace Microsoft.Data.SqlClient.SNI
     internal sealed partial class SslOverTdsStream
     {
         public override int Read(byte[] buffer, int offset, int count)
-        {
-            return Read(buffer.AsSpan(offset, count));
-        }
+            => Read(buffer.AsSpan(offset, count));
 
         public override void Write(byte[] buffer, int offset, int count)
-        {
-            Write(buffer.AsSpan(offset, count));
-        }
+            => Write(buffer.AsSpan(offset, count));
 
         public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-        {
-            return ReadAsync(new Memory<byte>(buffer, offset, count), cancellationToken).AsTask();
-        }
+            => ReadAsync(new Memory<byte>(buffer, offset, count), cancellationToken).AsTask();
 
         public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-        {
-            return WriteAsync(new ReadOnlyMemory<byte>(buffer, offset, count), cancellationToken).AsTask();
-        }
+            => WriteAsync(new ReadOnlyMemory<byte>(buffer, offset, count), cancellationToken).AsTask();
 
         public override int Read(Span<byte> buffer)
         {
@@ -288,7 +280,6 @@ public override async ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, Cancella
 
                         await _stream.FlushAsync().ConfigureAwait(false);
 
-
                         remaining = remaining.Slice(dataLength);
                     }
                 }

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlCommand.cs

@@ -1319,7 +1319,7 @@ private void ThrowIfReconnectionHasBeenCanceled()
             if (_stateObj == null)
             {
                 var reconnectionCompletionSource = _reconnectionCompletionSource;
-                if (reconnectionCompletionSource != null && reconnectionCompletionSource.Task.IsCanceled)
+                if (reconnectionCompletionSource != null && reconnectionCompletionSource.Task != null && reconnectionCompletionSource.Task.IsCanceled)
                 {
                     throw SQL.CR_ReconnectionCancelled();
                 }

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlUtil.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Data;
 using System.Diagnostics;
@@ -2131,4 +2132,5 @@ public static MethodInfo GetPromotedToken
             }
         }
     }
+
 }//namespace

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs

@@ -3266,7 +3266,7 @@ internal Task WritePacket(byte flushMode, bool canAccumulate = false)
 
             if (willCancel)
             {
-                // If we have been cancelled, then ensure that we write the ATTN packet as well
+                // If we have been canceled, then ensure that we write the ATTN packet as well
                 task = AsyncHelper.CreateContinuationTask(task, CancelWritePacket);
             }
             return task;