diff --git a/src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj b/src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj
index 07644b1355..a6be328a3a 100644
--- a/src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj
+++ b/src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj
@@ -466,6 +466,9 @@
     <Compile Include="..\..\src\Microsoft\Data\SqlClient\TdsParameterSetter.cs">
       <Link>Microsoft\Data\SqlClient\TdsParameterSetter.cs</Link>
     </Compile>
+    <Compile Include="..\..\src\Microsoft\Data\SqlClient\TdsParserStateObject.cs">
+      <Link>Microsoft\Data\SqlClient\TdsParserStateObject.cs</Link>
+    </Compile>
     <Compile Include="..\..\src\Microsoft\Data\SqlClient\TdsParserStaticMethods.cs">
       <Link>Microsoft\Data\SqlClient\TdsParserStaticMethods.cs</Link>
     </Compile>
diff --git a/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParser.cs b/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParser.cs
index ae6e6995cb..d1233d164a 100644
--- a/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParser.cs
+++ b/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParser.cs
@@ -259,6 +259,8 @@ internal EncryptionOptions EncryptionOptions
             }
         }
 
+        internal bool Is2005OrNewer => true;
+
         internal bool Is2008OrNewer
         {
             get
@@ -1327,7 +1329,7 @@ internal void ThrowExceptionAndWarning(TdsParserStateObject stateObj, bool calle
                     // report exception to pending async operation
                     // before OnConnectionClosed overrides the exception
                     // due to connection close notification through references
-                    var taskSource = stateObj._networkPacketTaskSource;
+                    TaskCompletionSource<object> taskSource = stateObj._networkPacketTaskSource;
                     if (taskSource != null)
                     {
                         taskSource.TrySetException(ADP.ExceptionWithStackTrace(exception));
@@ -1337,7 +1339,7 @@ internal void ThrowExceptionAndWarning(TdsParserStateObject stateObj, bool calle
                 if (asyncClose)
                 {
                     // Wait until we have the parser lock, then try to close
-                    var connHandler = _connHandler;
+                    SqlInternalConnectionTds connHandler = _connHandler;
                     Action<Action> wrapCloseAction = closeAction =>
                     {
                         Task.Factory.StartNew(() =>
@@ -2607,7 +2609,7 @@ private bool TryProcessEnvChange(int tokenLength, TdsParserStateObject stateObj,
 
             while (tokenLength > processedLength)
             {
-                var env = new SqlEnvChange();
+                SqlEnvChange env = new SqlEnvChange();
                 if (!stateObj.TryReadByte(out env._type))
                 {
                     return false;
@@ -3370,7 +3372,7 @@ private bool TryProcessDataClassification(TdsParserStateObject stateObj, out Sen
             {
                 return false;
             }
-            var labels = new List<Label>(numLabels);
+            List<Label> labels = new List<Label>(numLabels);
             for (ushort i = 0; i < numLabels; i++)
             {
                 if (!TryReadSensitivityLabel(stateObj, out string label, out string id))
@@ -3385,7 +3387,7 @@ private bool TryProcessDataClassification(TdsParserStateObject stateObj, out Sen
             {
                 return false;
             }
-            var informationTypes = new List<InformationType>(numInformationTypes);
+            List<InformationType> informationTypes = new List<InformationType>(numInformationTypes);
             for (ushort i = 0; i < numInformationTypes; i++)
             {
                 if (!TryReadSensitivityInformationType(stateObj, out string informationType, out string id))
@@ -3410,7 +3412,7 @@ private bool TryProcessDataClassification(TdsParserStateObject stateObj, out Sen
             {
                 return false;
             }
-            var columnSensitivities = new List<ColumnSensitivity>(numResultColumns);
+            List<ColumnSensitivity> columnSensitivities = new List<ColumnSensitivity>(numResultColumns);
             for (ushort columnNum = 0; columnNum < numResultColumns; columnNum++)
             {
                 // get sensitivity properties for all the different sources which were used in generating the column output
@@ -3418,7 +3420,7 @@ private bool TryProcessDataClassification(TdsParserStateObject stateObj, out Sen
                 {
                     return false;
                 }
-                var sensitivityProperties = new List<SensitivityProperty>(numSources);
+                List<SensitivityProperty> sensitivityProperties = new List<SensitivityProperty>(numSources);
                 for (ushort sourceNum = 0; sourceNum < numSources; sourceNum++)
                 {
                     // get the label index and then lookup label to use for source
@@ -4429,7 +4431,7 @@ internal void DrainData(TdsParserStateObject stateObj)
                 SqlDataReader.SharedState sharedState = stateObj._readerState;
                 if (sharedState != null && sharedState._dataReady)
                 {
-                    var metadata = stateObj._cleanupMetaData;
+                    _SqlMetaDataSet metadata = stateObj._cleanupMetaData;
                     if (stateObj._partialHeaderBytesRead > 0)
                     {
                         if (!stateObj.TryProcessHeader())
@@ -7473,12 +7475,12 @@ private Task WriteEncodingChar(string s, int numChars, int offset, Encoding enco
             else
             {
 #if NETFRAMEWORK || NETSTANDARD2_0
-                var charData = s.ToCharArray(offset, numChars);
-                var byteData = encoding.GetBytes(charData, 0, numChars);
+                char[] charData = s.ToCharArray(offset, numChars);
+                byte[] byteData = encoding.GetBytes(charData, 0, numChars);
                 Debug.Assert(byteData != null, "no data from encoding");
                 return stateObj.WriteByteArray(byteData, byteData.Length, 0, canAccumulate);
 #else
-                var byteData = encoding.GetBytes(s, offset, numChars);
+                byte[] byteData = encoding.GetBytes(s, offset, numChars);
                 Debug.Assert(byteData != null, "no data from encoding");
                 return stateObj.WriteByteArray(byteData, byteData.Length, 0, canAccumulate);
 #endif
@@ -9854,7 +9856,7 @@ private void WriteSmiParameter(SqlParameter param, int paramIndex, bool sendDefa
 
             if (advancedTraceIsOn)
             {
-                var sendDefaultValue = sendDefault ? 1 : 0;
+                int sendDefaultValue = sendDefault ? 1 : 0;
                 SqlClientEventSource.Log.TryAdvancedTraceEvent("<sc.TdsParser.WriteSmiParameter|ADV> {0}, Sending parameter '{1}', default flag={2}, metadata:{3}", ObjectID, param.ParameterName, sendDefaultValue, metaData.TraceString(3));
             }
 
diff --git a/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs b/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
index fbaa3dc480..f028922fc9 100644
--- a/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
+++ b/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
@@ -15,297 +15,21 @@
 
 namespace Microsoft.Data.SqlClient
 {
-    sealed internal class LastIOTimer
+    internal abstract partial class TdsParserStateObject
     {
-        internal long _value;
-    }
-
-    internal abstract class TdsParserStateObject
-    {
-        private static int _objectTypeCount; // EventSource counter
-        internal readonly int _objectID = Interlocked.Increment(ref _objectTypeCount);
-
-        [Flags]
-        internal enum SnapshottedStateFlags : byte
-        {
-            None = 0,
-            PendingData = 1 << 1,
-            OpenResult = 1 << 2,
-            ErrorTokenReceived = 1 << 3,  // Keep track of whether an error was received for the result. This is reset upon each done token
-            ColMetaDataReceived = 1 << 4, // Used to keep track of when to fire StatementCompleted event.
-            AttentionReceived = 1 << 5    // NOTE: Received is not volatile as it is only ever accessed\modified by TryRun its callees (i.e. single threaded access)
-        }
-
-        private sealed class TimeoutState
-        {
-            public const int Stopped = 0;
-            public const int Running = 1;
-            public const int ExpiredAsync = 2;
-            public const int ExpiredSync = 3;
-
-            private readonly int _value;
-
-            public TimeoutState(int value)
-            {
-                _value = value;
-            }
-
-            public int IdentityValue => _value;
-        }
-
-        private const int AttentionTimeoutSeconds = 5;
-
         private static readonly ContextCallback s_readAsyncCallbackComplete = ReadAsyncCallbackComplete;
 
-        // Ticks to consider a connection "good" after a successful I/O (10,000 ticks = 1 ms)
-        // The resolution of the timer is typically in the range 10 to 16 milliseconds according to msdn.
-        // We choose a value that is smaller than the likely timer resolution, but
-        // large enough to ensure that check connection execution will be 0.1% or less
-        // of very small open, query, close loops.
-        private const long CheckConnectionWindow = 50000;
-
-
-        protected readonly TdsParser _parser;                            // TdsParser pointer
-        private readonly WeakReference<object> _owner = new WeakReference<object>(null);   // the owner of this session, used to track when it's been orphaned
-        internal SqlDataReader.SharedState _readerState;                    // susbset of SqlDataReader state (if it is the owner) necessary for parsing abandoned results in TDS
-        private int _activateCount;                     // 0 when we're in the pool, 1 when we're not, all others are an error
-
-        // Two buffers exist in tdsparser, an in buffer and an out buffer.  For the out buffer, only
-        // one bookkeeping variable is needed, the number of bytes used in the buffer.  For the in buffer,
-        // three variables are actually needed.  First, we need to record from the netlib how many bytes it
-        // read from the netlib, this variable is _inBytesRead.  Then, we need to also keep track of how many
-        // bytes we have used as we consume the bytes from the buffer, that variable is _inBytesUsed.  Third,
-        // we need to keep track of how many bytes are left in the packet, so that we know when we have reached
-        // the end of the packet and so we need to consume the next header.  That variable is _inBytesPacket.
-
-        // Header length constants
-        internal readonly int _inputHeaderLen = TdsEnums.HEADER_LEN;
-        internal readonly int _outputHeaderLen = TdsEnums.HEADER_LEN;
-
-        // Out buffer variables
-        internal byte[] _outBuff;                                     // internal write buffer - initialize on login
-        internal int _outBytesUsed = TdsEnums.HEADER_LEN; // number of bytes used in internal write buffer -
-                                                          // - initialize past header
-                                                          // In buffer variables
-
-        /// <summary>
-        /// internal read buffer - initialize on login
-        /// </summary>
-        protected byte[] _inBuff;
-        /// <summary>
-        /// number of bytes used in internal read buffer
-        /// </summary>
-        internal int _inBytesUsed;
-        /// <summary>
-        /// number of bytes read into internal read buffer
-        /// </summary>
-        internal int _inBytesRead;
-
-        /// <summary>
-        /// number of bytes left in packet
-        /// </summary>
-        internal int _inBytesPacket;
-
-        internal int _spid;                                 // SPID of the current connection
-
-        // Packet state variables
-        internal byte _outputMessageType;                   // tds header type
-        internal byte _messageStatus;                       // tds header status
-        internal byte _outputPacketNumber = 1;              // number of packets sent to server in message - start at 1 per ramas
-        internal uint _outputPacketCount;
-        internal volatile bool _fResetEventOwned;           // ResetEvent serializing call to sp_reset_connection
-        internal volatile bool _fResetConnectionSent;       // For multiple packet execute
-        internal bool _bulkCopyOpperationInProgress;        // Set to true during bulk copy and used to turn toggle write timeouts.
-        internal bool _bulkCopyWriteTimeout;                // Set to trun when _bulkCopyOperationInProgress is trun and write timeout happens
-
-        // SNI variables
-        /// <summary>
-        /// Used to synchronize access to _writePacketCache and _pendingWritePackets
-        /// </summary>
-        protected readonly object _writePacketLockObject = new object();
-
-        // Async variables
-        private int _pendingCallbacks;                      // we increment this before each async read/write call and decrement it in the callback.  We use this to determine when to release the GcHandle...
-
         // Timeout variables
-        private long _timeoutMilliseconds;
-        private long _timeoutTime;                          // variable used for timeout computations, holds the value of the hi-res performance counter at which this request should expire
-        private int _timeoutState; // expected to be one of the constant values TimeoutStopped, TimeoutRunning, TimeoutExpiredAsync, TimeoutExpiredSync
-        private int _timeoutIdentitySource;
-        private volatile int _timeoutIdentityValue;
-        internal volatile bool _attentionSent;              // true if we sent an Attention to the server
-        internal volatile bool _attentionSending;
-        private readonly TimerCallback _onTimeoutAsync;
-
-        // Below 2 properties are used to enforce timeout delays in code to 
-        // reproduce issues related to theadpool starvation and timeout delay.
-        // It should always be set to false by default, and only be enabled during testing.
-        internal bool _enforceTimeoutDelay = false;
-        internal int _enforcedTimeoutDelayInMilliSeconds = 5000;
-
-        private readonly LastIOTimer _lastSuccessfulIOTimer;
-
-        // secure password information to be stored
-        //  At maximum number of secure string that need to be stored is two; one for login password and the other for new change password
-        private SecureString[] _securePasswords = new SecureString[2] { null, null };
-        private int[] _securePasswordOffsetsInBuffer = new int[2];
-
-        // This variable is used to track whether another thread has requested a cancel.  The
-        // synchronization points are
-        //   On the user's execute thread:
-        //     1) the first packet write
-        //     2) session close - return this stateObj to the session pool
-        //   On cancel thread we only have the cancel call.
-        // Currently all access to this variable is inside a lock, The state diagram is:
-        // 1) pre first packet write, if cancel is requested, set variable so exception is triggered
-        //    on user thread when first packet write is attempted
-        // 2) post first packet write, but before session return - a call to cancel will send an
-        //    attention to the server
-        // 3) post session close - no attention is allowed
-        private bool _cancelled;
-        private const int _waitForCancellationLockPollTimeout = 100;
-        private WeakReference _cancellationOwner = new WeakReference(null);
-
-        // Cache the transaction for which this command was executed so upon completion we can
-        // decrement the appropriate result count.
-        internal SqlInternalTransaction _executedUnderTransaction;
-
-        // TDS stream processing variables
-        internal ulong _longlen;                                     // plp data length indicator
-        internal ulong _longlenleft;                                 // Length of data left to read (64 bit lengths)
-        internal int[] _decimalBits;                // scratch buffer for decimal/numeric data
-        internal byte[] _bTmp = new byte[TdsEnums.SQL2005_HEADER_LEN];  // Scratch buffer for misc use
-        internal int _bTmpRead;                   // Counter for number of temporary bytes read
-        internal Decoder _plpdecoder;             // Decoder object to process plp character data
-        internal bool _accumulateInfoEvents;               // TRUE - accumulate info messages during TdsParser.Run, FALSE - fire them
-        internal List<SqlError> _pendingInfoEvents;
-        internal byte[] _bLongBytes;                 // scratch buffer to serialize Long values (8 bytes).
-        internal byte[] _bIntBytes;                 // scratch buffer to serialize Int values (4 bytes).
-        internal byte[] _bShortBytes;                 // scratch buffer to serialize Short values (2 bytes).
-        internal byte[] _bDecimalBytes;                 // scratch buffer to serialize decimal values (17 bytes).
-
-
-        //
-        // DO NOT USE THIS BUFFER FOR OTHER THINGS.
-        // ProcessHeader can be called ANYTIME while doing network reads.
-        private byte[] _partialHeaderBuffer = new byte[TdsEnums.HEADER_LEN];   // Scratch buffer for ProcessHeader
-        internal int _partialHeaderBytesRead;
-
-        internal _SqlMetaDataSet _cleanupMetaData;
-        internal _SqlMetaDataSetCollection _cleanupAltMetaDataSetArray;
-
-        private SniContext _sniContext = SniContext.Undefined;
-#if DEBUG
-        private SniContext _debugOnlyCopyOfSniContext = SniContext.Undefined;
-#endif
-
-        private bool _bcpLock = false;
-
-        // Null bitmap compression (NBC) information for the current row
-        private NullBitmap _nullBitmapInfo;
+        private readonly WeakReference _cancellationOwner = new WeakReference(null);
 
-        // Async
-        internal TaskCompletionSource<object> _networkPacketTaskSource;
-        private Timer _networkPacketTimeout;
-        internal bool _syncOverAsync = true;
-        private bool _snapshotReplay;
-        private StateSnapshot _snapshot;
+		// Async
         private StateSnapshot _cachedSnapshot;
         private SnapshottedStateFlags _snapshottedState;
-        internal ExecutionContext _executionContext;
-        internal bool _asyncReadWithoutSnapshot;
-#if DEBUG
-        // Used to override the assert than ensures that the stacktraces on subsequent replays are the same
-        // This is useful is you are purposefully running the replay from a different thread (e.g. during SqlDataReader.Close)
-        internal bool _permitReplayStackTraceToDiffer;
-
-        // Used to indicate that the higher level object believes that this stateObj has enough data to complete an operation
-        // If this stateObj has to read, then it will raise an assert
-        internal bool _shouldHaveEnoughData;
-#endif
-
-        // local exceptions to cache warnings and errors
-        internal SqlErrorCollection _errors;
-        internal SqlErrorCollection _warnings;
-        internal object _errorAndWarningsLock = new object();
-        private bool _hasErrorOrWarning;
-
-        // local exceptions to cache warnings and errors that occurred prior to sending attention
-        internal SqlErrorCollection _preAttentionErrors;
-        internal SqlErrorCollection _preAttentionWarnings;
-
-        private volatile TaskCompletionSource<object> _writeCompletionSource;
-        protected volatile int _asyncWriteCount;
-        private volatile Exception _delayedWriteAsyncCallbackException; // set by write async callback if completion source is not yet created
-
-        // _readingcount is incremented when we are about to read.
-        // We check the parser state afterwards.
-        // When the read is completed, we decrement it before handling errors
-        // as the error handling may end up calling Dispose.
-        private int _readingCount;
-
-        // Test hooks
-#if DEBUG
-        // This is a test hook to enable testing of the retry paths.
-        // When set to true, almost every possible retry point will be attempted.
-        // This will drastically impact performance.
-        //
-        // Sample code to enable:
-        //
-        //    Type type = typeof(SqlDataReader).Assembly.GetType("Microsoft.Data.SqlClient.TdsParserStateObject");
-        //    System.Reflection.FieldInfo field = type.GetField("_forceAllPends", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static);
-        //    if (field != null) {
-        //        field.SetValue(null, true);
-        //    }
-        //
-        internal static bool _forceAllPends = false;
-
-        // set this while making a call that should not block.
-        // instead of blocking it will fail.
-        internal static bool _failAsyncPends = false;
-
-        // If this is set and an async read is made, then
-        // we will switch to syncOverAsync mode for the
-        // remainder of the async operation.
-        internal static bool _forceSyncOverAsyncAfterFirstPend = false;
-
-        // Requests to send attention will be ignored when _skipSendAttention is true.
-        // This is useful to simulate circumstances where timeouts do not recover.
-        internal static bool _skipSendAttention = false;
-
-        // Prevents any pending read from completing until the user signals it using
-        // CompletePendingReadWithSuccess() or CompletePendingReadWithFailure(int errorCode) in SqlCommand\SqlDataReader
-        internal static bool _forcePendingReadsToWaitForUser = false;
-        internal TaskCompletionSource<object> _realNetworkPacketTaskSource;
-
-        // Field is never assigned to, and will always have its default value
-#pragma warning disable 0649
-        // Set to true to enable checking the call stacks match when packet retry occurs.
-        internal static bool _checkNetworkPacketRetryStacks = false;
-#pragma warning restore 0649
-#endif
 
         //////////////////
         // Constructors //
         //////////////////
 
-        internal TdsParserStateObject(TdsParser parser)
-        {
-            // Construct a physical connection
-            Debug.Assert(null != parser, "no parser?");
-            _parser = parser;
-            _onTimeoutAsync = OnTimeoutAsync;
-
-            // For physical connection, initialize to default login packet size.
-            SetPacketSize(TdsEnums.DEFAULT_LOGIN_PACKET_SIZE);
-
-            // we post a callback that represents the call to dispose; once the
-            // object is disposed, the next callback will cause the GC Handle to
-            // be released.
-            IncrementPendingCallbacks();
-            _lastSuccessfulIOTimer = new LastIOTimer();
-        }
-
         internal TdsParserStateObject(TdsParser parser, TdsParserStateObject physicalConnection, bool async)
         {
             // Construct a MARS session
@@ -341,94 +65,11 @@ internal TdsParserStateObject(TdsParser parser, TdsParserStateObject physicalCon
         ////////////////
         // Properties //
         ////////////////
-
-        // BcpLock - use to lock this object if there is a potential risk of using this object
-        // between tds packets
-        internal bool BcpLock
-        {
-            get
-            {
-                return _bcpLock;
-            }
-            set
-            {
-                _bcpLock = value;
-            }
-        }
-
-#if DEBUG
-        internal SniContext DebugOnlyCopyOfSniContext
-        {
-            get
-            {
-                return _debugOnlyCopyOfSniContext;
-            }
-        }
-
-        internal void InvalidateDebugOnlyCopyOfSniContext()
-        {
-            _debugOnlyCopyOfSniContext = SniContext.Undefined;
-        }
-#endif
-
-        internal bool IsOrphaned
-        {
-            get
-            {
-                bool isAlive = _owner.TryGetTarget(out object target);
-                Debug.Assert((0 == _activateCount && !isAlive) // in pool
-                             || (1 == _activateCount && isAlive && target != null)
-                             || (1 == _activateCount && !isAlive), "Unknown state on TdsParserStateObject.IsOrphaned!");
-                return (0 != _activateCount && !isAlive);
-            }
-        }
-
-        internal object Owner
-        {
-            set
-            {
-                Debug.Assert(value == null || !_owner.TryGetTarget(out object target) || value is SqlDataReader reader1 && reader1.Command == target, "Should not be changing the owner of an owned stateObj");
-                if (value is SqlDataReader reader)
-                {
-                    _readerState = reader._sharedState;
-                }
-                else
-                {
-                    _readerState = null;
-                }
-                _owner.SetTarget(value);
-            }
-        }
-
         internal abstract uint DisableSsl();
 
-        internal bool HasOwner => _owner.TryGetTarget(out object _);
-
-        internal TdsParser Parser
-        {
-            get
-            {
-                return _parser;
-            }
-        }
 
         internal abstract uint EnableMars(ref uint info);
 
-        internal SniContext SniContext
-        {
-            get
-            {
-                return _sniContext;
-            }
-            set
-            {
-                _sniContext = value;
-#if DEBUG
-                _debugOnlyCopyOfSniContext = value;
-#endif
-            }
-        }
-
         internal abstract uint Status
         {
             get;
@@ -439,112 +80,8 @@ internal abstract SessionHandle SessionHandle
             get;
         }
 
-        internal bool TimeoutHasExpired
-        {
-            get
-            {
-                Debug.Assert(0 == _timeoutMilliseconds || 0 == _timeoutTime, "_timeoutTime hasn't been reset");
-                return TdsParserStaticMethods.TimeoutHasExpired(_timeoutTime);
-            }
-        }
-
-        internal long TimeoutTime
-        {
-            get
-            {
-                if (0 != _timeoutMilliseconds)
-                {
-                    _timeoutTime = TdsParserStaticMethods.GetTimeout(_timeoutMilliseconds);
-                    _timeoutMilliseconds = 0;
-                }
-                return _timeoutTime;
-            }
-            set
-            {
-                _timeoutMilliseconds = 0;
-                _timeoutTime = value;
-            }
-        }
-
-        internal int GetTimeoutRemaining()
-        {
-            int remaining;
-            if (0 != _timeoutMilliseconds)
-            {
-                remaining = (int)Math.Min((long)int.MaxValue, _timeoutMilliseconds);
-                _timeoutTime = TdsParserStaticMethods.GetTimeout(_timeoutMilliseconds);
-                _timeoutMilliseconds = 0;
-            }
-            else
-            {
-                remaining = TdsParserStaticMethods.GetTimeoutMilliseconds(_timeoutTime);
-            }
-            return remaining;
-        }
-
-        internal bool TryStartNewRow(bool isNullCompressed, int nullBitmapColumnsCount = 0)
-        {
-            Debug.Assert(!isNullCompressed || nullBitmapColumnsCount > 0, "Null-Compressed row requires columns count");
-
-            if (_snapshot != null)
-            {
-                _snapshot.CloneNullBitmapInfo();
-            }
-
-            // initialize or unset null bitmap information for the current row
-            if (isNullCompressed)
-            {
-                // assert that NBCROW is not in use by 2005 or before
-                Debug.Assert(_parser.Is2008OrNewer, "NBCROW is sent by pre-2008 server");
-
-                if (!_nullBitmapInfo.TryInitialize(this, nullBitmapColumnsCount))
-                {
-                    return false;
-                }
-            }
-            else
-            {
-                _nullBitmapInfo.Clean();
-            }
-
-            return true;
-        }
-
-        internal bool IsRowTokenReady()
-        {
-            // Removing one byte since TryReadByteArray\TryReadByte will aggressively read the next packet if there is no data left - so we need to ensure there is a spare byte
-            int bytesRemaining = Math.Min(_inBytesPacket, _inBytesRead - _inBytesUsed) - 1;
-
-            if (bytesRemaining > 0)
-            {
-                if (_inBuff[_inBytesUsed] == TdsEnums.SQLROW)
-                {
-                    // At a row token, so we're ready
-                    return true;
-                }
-                else if (_inBuff[_inBytesUsed] == TdsEnums.SQLNBCROW)
-                {
-                    // NBC row token, ensure that we have enough data for the bitmap
-                    // SQLNBCROW + Null Bitmap (copied from NullBitmap.TryInitialize)
-                    int bytesToRead = 1 + (_cleanupMetaData.Length + 7) / 8;
-                    return (bytesToRead <= bytesRemaining);
-                }
-            }
-
-            // No data left, or not at a row token
-            return false;
-        }
-
-        internal bool IsNullCompressionBitSet(int columnOrdinal)
-        {
-            return _nullBitmapInfo.IsGuaranteedNull(columnOrdinal);
-        }
-
-        private struct NullBitmap
+        private partial struct NullBitmap
         {
-            private byte[] _nullBitmap;
-            private int _columnsCount; // set to 0 if not used or > 0 for NBC rows
-
             internal bool TryInitialize(TdsParserStateObject stateObj, int columnsCount)
             {
                 _columnsCount = columnsCount;
@@ -568,61 +105,12 @@ internal bool TryInitialize(TdsParserStateObject stateObj, int columnsCount)
                 SqlClientEventSource.Log.TryAdvancedTraceBinEvent("TdsParserStateObject.NullBitmap.Initialize | INFO | ADV | State Object Id {0}, Null Bitmap length {1}, NBCROW bitmap data: {2}", stateObj._objectID, (ushort)_nullBitmap.Length, _nullBitmap);
                 return true;
             }
-
-            internal bool ReferenceEquals(NullBitmap obj)
-            {
-                return object.ReferenceEquals(_nullBitmap, obj._nullBitmap);
-            }
-
-            internal NullBitmap Clone()
-            {
-                NullBitmap newBitmap = new NullBitmap();
-                newBitmap._nullBitmap = _nullBitmap == null ? null : (byte[])_nullBitmap.Clone();
-                newBitmap._columnsCount = _columnsCount;
-                return newBitmap;
-            }
-
-            internal void Clean()
-            {
-                _columnsCount = 0;
-                // no need to free _nullBitmap array - it is cached for the next row
-            }
-
-            /// <summary>
-            /// If this method returns true, the value is guaranteed to be null. This is not true vice versa:
-            /// if the bitmap value is false (if this method returns false), the value can be either null or non-null - no guarantee in this case.
-            /// To determine whether it is null or not, read it from the TDS (per NBCROW design spec, for IMAGE/TEXT/NTEXT columns server might send
-            /// bitmap = 0, when the actual value is null).
-            /// </summary>
-            internal bool IsGuaranteedNull(int columnOrdinal)
-            {
-                if (_columnsCount == 0)
-                {
-                    // not an NBC row
-                    return false;
-                }
-
-                Debug.Assert(columnOrdinal >= 0 && columnOrdinal < _columnsCount, "Invalid column ordinal");
-
-                byte testBit = (byte)(1 << (columnOrdinal & 0x7)); // columnOrdinal & 0x7 == columnOrdinal MOD 0x7
-                byte testByte = _nullBitmap[columnOrdinal >> 3];
-                return (testBit & testByte) != 0;
-            }
         }
 
         /////////////////////
         // General methods //
         /////////////////////
 
-        // If this object is part of a TdsParserSessionPool, then this *must* be called inside the pool's lock
-        internal void Activate(object owner)
-        {
-            Debug.Assert(_parser.MARSOn, "Can not activate a non-MARS connection");
-            Owner = owner; // must assign an owner for reclamation to work
-            int result = Interlocked.Increment(ref _activateCount);   // must have non-zero activation count for reclamation to work too.
-            Debug.Assert(result == 1, "invalid deactivate count");
-        }
-
         // This method is only called by the command or datareader as a result of a user initiated
         // cancel request.
         internal void Cancel(object caller)
@@ -636,7 +124,7 @@ internal void Cancel(object caller)
                 // Keep looping until we either grabbed the lock (and therefore sent attention) or the connection closes\breaks
                 while ((!hasLock) && (_parser.State != TdsParserState.Closed) && (_parser.State != TdsParserState.Broken))
                 {
-                    Monitor.TryEnter(this, _waitForCancellationLockPollTimeout, ref hasLock);
+                    Monitor.TryEnter(this, WaitForCancellationLockPollTimeout, ref hasLock);
                     if (hasLock)
                     { // Lock for the time being - since we need to synchronize the attention send.
                       // This lock is also protecting against concurrent close and async continuations
@@ -654,7 +142,7 @@ internal void Cancel(object caller)
                                 {
                                     try
                                     {
-                                        _parser.Connection._parserLock.Wait(canReleaseFromAnyThread: false, timeout: _waitForCancellationLockPollTimeout, lockTaken: ref hasParserLock);
+                                        _parser.Connection._parserLock.Wait(canReleaseFromAnyThread: false, timeout: WaitForCancellationLockPollTimeout, lockTaken: ref hasParserLock);
                                         if (hasParserLock)
                                         {
                                             _parser.Connection.ThreadHasParserLockForClose = true;
@@ -687,82 +175,6 @@ internal void Cancel(object caller)
             }
         }
 
-        // CancelRequest - use to cancel while writing a request to the server
-        //
-        // o none of the request might have been sent to the server, simply reset the buffer,
-        //   sending attention does not hurt
-        // o the request was partially written. Send an ignore header to the server. attention is
-        //   required if the server was waiting for data (e.g. insert bulk rows)
-        // o the request was completely written out and the server started to process the request.
-        //   attention is required to have the server stop processing.
-        //
-        internal void CancelRequest()
-        {
-            ResetBuffer();    // clear out unsent buffer
-            // If the first sqlbulkcopy timeout, _outputPacketNumber may not be 1,
-            // the next sqlbulkcopy (same connection string) requires this to be 1, hence reset
-            // it here when exception happens in the first sqlbulkcopy
-            ResetPacketCounters();
-
-            // VSDD#907507, if bulkcopy write timeout happens, it already sent the attention,
-            // so no need to send it again
-            if (!_bulkCopyWriteTimeout)
-            {
-                SendAttention();
-                Parser.ProcessPendingAck(this);
-            }
-        }
-
-        public void CheckSetResetConnectionState(uint error, CallbackType callbackType)
-        {
-            // Should only be called for MARS - that is the only time we need to take
-            // the ResetConnection lock!
-
-            // It was raised in a security review by Microsoft questioning whether
-            // we need to actually process the resulting packet (sp_reset ack or error) to know if the
-            // reset actually succeeded.  There was a concern that if the reset failed and we proceeded
-            // there might be a security issue present.  We have been assured by the server that if
-            // sp_reset fails, they guarantee they will kill the resulting connection.  So - it is
-            // safe for us to simply receive the packet and then consume the pre-login later.
-
-            Debug.Assert(_parser.MARSOn, "Should not be calling CheckSetResetConnectionState on non MARS connection");
-
-            if (_fResetEventOwned)
-            {
-                if (callbackType == CallbackType.Read && TdsEnums.SNI_SUCCESS == error)
-                {
-                    // RESET SUCCEEDED!
-                    // If we are on read callback and no error occurred (and we own reset event) -
-                    // then we sent the sp_reset_connection and so we need to reset sp_reset_connection
-                    // flag to false, and then release the ResetEvent.
-                    _parser._fResetConnection = false;
-                    _fResetConnectionSent = false;
-                    _fResetEventOwned = !_parser._resetConnectionEvent.Set();
-                    Debug.Assert(!_fResetEventOwned, "Invalid AutoResetEvent state!");
-                }
-
-                if (TdsEnums.SNI_SUCCESS != error)
-                {
-                    // RESET FAILED!
-
-                    // If write or read failed with reset, we need to clear event but not mark connection
-                    // as reset.
-                    _fResetConnectionSent = false;
-                    _fResetEventOwned = !_parser._resetConnectionEvent.Set();
-                    Debug.Assert(!_fResetEventOwned, "Invalid AutoResetEvent state!");
-                }
-            }
-        }
-
-        internal void CloseSession()
-        {
-            ResetCancelAndProcessAttention();
-#if DEBUG
-            InvalidateDebugOnlyCopyOfSniContext();
-#endif
-            Parser.PutSession(this);
-        }
-
         private void ResetCancelAndProcessAttention()
         {
             // This method is shared by CloseSession initiated by DataReader.Close or completed
@@ -845,69 +257,6 @@ internal abstract void CreatePhysicalSNIHandle(
 
         internal abstract uint GenerateSspiClientContext(byte[] receivedBuff, uint receivedLength, ref byte[] sendBuff, ref uint sendLength, byte[][] _sniSpnBuffer);
 
-        internal bool Deactivate()
-        {
-            bool goodForReuse = false;
-
-            try
-            {
-                TdsParserState state = Parser.State;
-                if (state != TdsParserState.Broken && state != TdsParserState.Closed)
-                {
-                    if (HasPendingData)
-                    {
-                        Parser.DrainData(this); // This may throw - taking us to catch block.c
-                    }
-
-                    if (HasOpenResult)
-                    {
-                        DecrementOpenResultCount();
-                    }
-
-                    ResetCancelAndProcessAttention();
-                    goodForReuse = true;
-                }
-            }
-            catch (Exception e)
-            {
-                if (!ADP.IsCatchableExceptionType(e))
-                {
-                    throw;
-                }
-            }
-            return goodForReuse;
-        }
-
-        // If this object is part of a TdsParserSessionPool, then this *must* be called inside the pool's lock
-        internal void RemoveOwner()
-        {
-            if (_parser.MARSOn)
-            {
-                // We only care about the activation count for MARS connections
-                int result = Interlocked.Decrement(ref _activateCount);   // must have non-zero activation count for reclamation to work too.
-                Debug.Assert(result == 0, "invalid deactivate count");
-            }
-            Owner = null;
-        }
-
-        internal void DecrementOpenResultCount()
-        {
-            if (_executedUnderTransaction == null)
-            {
-                // If we were not executed under a transaction - decrement the global count
-                // on the parser.
-                SqlClientEventSource.Log.TryTraceEvent("TdsParserStateObject.DecrementOpenResultCount | INFO | State Object Id {0}, Processing Attention.", _objectID);
-                _parser.DecrementNonTransactedOpenResultCount();
-            }
-            else
-            {
-                // If we were executed under a transaction - decrement the count on the transaction.
-                _executedUnderTransaction.DecrementAndObtainOpenResultCount();
-                _executedUnderTransaction = null;
-            }
-            HasOpenResult = false;
-        }
-
         internal int DecrementPendingCallbacks(bool release)
         {
             int remaining = Interlocked.Decrement(ref _pendingCallbacks);
@@ -919,48 +268,6 @@ internal int DecrementPendingCallbacks(bool release)
             return remaining;
         }
 
-        internal void DisposeCounters()
-        {
-            Timer networkPacketTimeout = _networkPacketTimeout;
-            if (networkPacketTimeout != null)
-            {
-                _networkPacketTimeout = null;
-                networkPacketTimeout.Dispose();
-            }
-
-            Debug.Assert(Volatile.Read(ref _readingCount) >= 0, "_readingCount is negative");
-            if (Volatile.Read(ref _readingCount) > 0)
-            {
-                // if _reading is true, we need to wait for it to complete
-                // if _reading is false, then future read attempts will
-                // already see the null _sessionHandle and abort.
-
-                // We block after nulling _sessionHandle but before disposing it
-                // to give a chance for a read that has already grabbed the
-                // handle to complete.
-                SpinWait.SpinUntil(() => Volatile.Read(ref _readingCount) == 0);
-            }
-        }
-
-        internal int IncrementAndObtainOpenResultCount(SqlInternalTransaction transaction)
-        {
-            HasOpenResult = true;
-
-            if (transaction == null)
-            {
-                // If we are not passed a transaction, we are not executing under a transaction
-                // and thus we should increment the global connection result count.
-                return _parser.IncrementNonTransactedOpenResultCount();
-            }
-            else
-            {
-                // If we are passed a transaction, we are executing under a transaction
-                // and thus we should increment the transaction's result count.
-                _executedUnderTransaction = transaction;
-                return transaction.IncrementAndObtainOpenResultCount();
-            }
-        }
-
         internal int IncrementPendingCallbacks()
         {
             int remaining = Interlocked.Increment(ref _pendingCallbacks);
@@ -969,236 +276,11 @@ internal int IncrementPendingCallbacks()
             return remaining;
         }
 
-        internal void SetTimeoutSeconds(int timeout)
-        {
-            SetTimeoutMilliseconds((long)timeout * 1000L);
-        }
-
-        internal void SetTimeoutMilliseconds(long timeout)
-        {
-            if (timeout <= 0)
-            {
-                // 0 or less (i.e. Timespan.Infinite) == infinite (which is represented by Int64.MaxValue)
-                _timeoutMilliseconds = 0;
-                _timeoutTime = long.MaxValue;
-            }
-            else
-            {
-                _timeoutMilliseconds = timeout;
-                _timeoutTime = 0;
-            }
-        }
-
         internal void StartSession(object cancellationOwner)
         {
             _cancellationOwner.Target = cancellationOwner;
         }
 
-        internal void ThrowExceptionAndWarning(bool callerHasConnectionLock = false, bool asyncClose = false)
-        {
-            _parser.ThrowExceptionAndWarning(this, callerHasConnectionLock, asyncClose);
-        }
-
-        ////////////////////////////////////////////
-        // TDS Packet/buffer manipulation methods //
-        ////////////////////////////////////////////
-
-        internal Task ExecuteFlush()
-        {
-            lock (this)
-            {
-                if (_cancelled && 1 == _outputPacketNumber)
-                {
-                    ResetBuffer();
-                    _cancelled = false;
-                    throw SQL.OperationCancelled();
-                }
-                else
-                {
-                    Task writePacketTask = WritePacket(TdsEnums.HARDFLUSH);
-                    if (writePacketTask == null)
-                    {
-                        HasPendingData = true;
-                        _messageStatus = 0;
-                        return null;
-                    }
-                    else
-                    {
-                        return AsyncHelper.CreateContinuationTaskWithState(
-                            task: writePacketTask,
-                            state: this,
-                            onSuccess: static (object state) =>
-                            {
-                                TdsParserStateObject stateObject = (TdsParserStateObject)state;
-                                stateObject.HasPendingData = true;
-                                stateObject._messageStatus = 0;
-                            }
-                        );
-                    }
-                }
-            }
-        }
-
-        // Processes the tds header that is present in the buffer
-        internal bool TryProcessHeader()
-        {
-            Debug.Assert(_inBytesPacket == 0, "there should not be any bytes left in packet when ReadHeader is called");
-
-            // if the header splits buffer reads - special case!
-            if ((_partialHeaderBytesRead > 0) || (_inBytesUsed + _inputHeaderLen > _inBytesRead))
-            {
-                // VSTS 219884: when some kind of MITM (man-in-the-middle) tool splits the network packets, the message header can be split over
-                // several network packets.
-                // Note: cannot use ReadByteArray here since it uses _inBytesPacket which is not set yet.
-                do
-                {
-                    int copy = Math.Min(_inBytesRead - _inBytesUsed, _inputHeaderLen - _partialHeaderBytesRead);
-                    Debug.Assert(copy > 0, "ReadNetworkPacket read empty buffer");
-
-                    Buffer.BlockCopy(_inBuff, _inBytesUsed, _partialHeaderBuffer, _partialHeaderBytesRead, copy);
-                    _partialHeaderBytesRead += copy;
-                    _inBytesUsed += copy;
-
-                    Debug.Assert(_partialHeaderBytesRead <= _inputHeaderLen, "Read more bytes for header than required");
-                    if (_partialHeaderBytesRead == _inputHeaderLen)
-                    {
-                        // All read
-                        _partialHeaderBytesRead = 0;
-                        _inBytesPacket = ((int)_partialHeaderBuffer[TdsEnums.HEADER_LEN_FIELD_OFFSET] << 8 |
-                                  (int)_partialHeaderBuffer[TdsEnums.HEADER_LEN_FIELD_OFFSET + 1]) - _inputHeaderLen;
-
-                        _messageStatus = _partialHeaderBuffer[1];
-                        _spid = _partialHeaderBuffer[TdsEnums.SPID_OFFSET] << 8 |
-                                  _partialHeaderBuffer[TdsEnums.SPID_OFFSET + 1];
-                        SqlClientEventSource.Log.TryAdvancedTraceEvent("TdsParserStateObject.TryProcessHeader | ADV | State Object Id {0}, Client Connection Id {1}, Server process Id (SPID) {2}", _objectID, _parser?.Connection?.ClientConnectionId, _spid);
-                    }
-                    else
-                    {
-                        Debug.Assert(_inBytesUsed == _inBytesRead, "Did not use all data while reading partial header");
-
-                        // Require more data
-                        if (_parser.State == TdsParserState.Broken || _parser.State == TdsParserState.Closed)
-                        {
-                            // NOTE: ReadNetworkPacket does nothing if the parser state is closed or broken
-                            // to avoid infinite loop, we raise an exception
-                            ThrowExceptionAndWarning();
-                            return true;
-                        }
-
-                        if (!TryReadNetworkPacket())
-                        {
-                            return false;
-                        }
-
-                        if (IsTimeoutStateExpired)
-                        {
-                            ThrowExceptionAndWarning();
-                            return true;
-                        }
-                    }
-                } while (_partialHeaderBytesRead != 0); // This is reset to 0 once we have read everything that we need
-
-                AssertValidState();
-            }
-            else
-            {
-                // normal header processing...
-                _messageStatus = _inBuff[_inBytesUsed + 1];
-                _inBytesPacket = (_inBuff[_inBytesUsed + TdsEnums.HEADER_LEN_FIELD_OFFSET] << 8 |
-                                              _inBuff[_inBytesUsed + TdsEnums.HEADER_LEN_FIELD_OFFSET + 1]) - _inputHeaderLen;
-                _spid = _inBuff[_inBytesUsed + TdsEnums.SPID_OFFSET] << 8 |
-                                              _inBuff[_inBytesUsed + TdsEnums.SPID_OFFSET + 1];
-                SqlClientEventSource.Log.TryAdvancedTraceEvent("TdsParserStateObject.TryProcessHeader | ADV | State Object Id {0}, Client Connection Id {1}, Server process Id (SPID) {2}", _objectID, _parser?.Connection?.ClientConnectionId, _spid);
-                _inBytesUsed += _inputHeaderLen;
-
-                AssertValidState();
-            }
-
-            if (_inBytesPacket < 0)
-            {
-                // either TDS stream is corrupted or there is multithreaded misuse of connection
-                throw SQL.ParsingError();
-            }
-
-            return true;
-        }
-
-        // This ensure that there is data available to be read in the buffer and that the header has been processed
-        // NOTE: This method (and all it calls) should be retryable without replaying a snapshot
-        internal bool TryPrepareBuffer()
-        {
-            Debug.Assert(_inBuff != null, "packet buffer should not be null!");
-
-            // Header spans packets, or we haven't read the header yet - process header
-            if ((_inBytesPacket == 0) && (_inBytesUsed < _inBytesRead))
-            {
-                if (!TryProcessHeader())
-                {
-                    return false;
-                }
-                Debug.Assert(_inBytesPacket != 0, "_inBytesPacket cannot be 0 after processing header!");
-                AssertValidState();
-            }
-
-            // If we're out of data, need to read more
-            if (_inBytesUsed == _inBytesRead)
-            {
-                // If the _inBytesPacket is not zero, then we have data left in the packet, but the data in the packet
-                // spans the buffer, so we can read any amount of data possible, and we do not need to call ProcessHeader
-                // because there isn't a header at the beginning of the data that we are reading.
-                if (_inBytesPacket > 0)
-                {
-                    if (!TryReadNetworkPacket())
-                    {
-                        return false;
-                    }
-                }
-                else if (_inBytesPacket == 0)
-                {
-                    // Else we have finished the packet and so we must read as much data as possible
-                    if (!TryReadNetworkPacket())
-                    {
-                        return false;
-                    }
-
-                    if (!TryProcessHeader())
-                    {
-                        return false;
-                    }
-
-                    Debug.Assert(_inBytesPacket != 0, "_inBytesPacket cannot be 0 after processing header!");
-                    if (_inBytesUsed == _inBytesRead)
-                    {
-                        // we read a header but didn't get anything else except it
-                        // VSTS 219884: it can happen that the TDS packet header and its data are split across two network packets.
-                        // Read at least one more byte to get/cache the first data portion of this TDS packet
-                        if (!TryReadNetworkPacket())
-                        {
-                            return false;
-                        }
-                    }
-                }
-                else
-                {
-                    Debug.Fail("entered negative _inBytesPacket loop");
-                }
-                AssertValidState();
-            }
-
-            return true;
-        }
-
-        internal void ResetBuffer()
-        {
-            _outBytesUsed = _outputHeaderLen;
-        }
-
-        internal void ResetPacketCounters()
-        {
-            _outputPacketNumber = 1;
-            _outputPacketCount = 0;
-        }
-
         private void SetSnapshottedState(SnapshottedStateFlags flag, bool value)
         {
             if (value)
@@ -1246,81 +328,6 @@ internal bool HasReceivedColumnMetadata
             set => SetSnapshottedState(SnapshottedStateFlags.ColMetaDataReceived, value);
         }
 
-
-        internal bool SetPacketSize(int size)
-        {
-            if (size > TdsEnums.MAX_PACKET_SIZE)
-            {
-                throw SQL.InvalidPacketSize();
-            }
-            Debug.Assert(size >= 1, "Cannot set packet size to less than 1.");
-            Debug.Assert((_outBuff == null && _inBuff == null) ||
-                          (_outBuff.Length == _inBuff.Length),
-                          "Buffers are not in consistent state");
-            Debug.Assert((_outBuff == null && _inBuff == null) ||
-                          this == _parser._physicalStateObj,
-                          "SetPacketSize should only be called on a stateObj with null buffers on the physicalStateObj!");
-            Debug.Assert(_inBuff == null
-                          || (
-                          _outBytesUsed == (_outputHeaderLen + BitConverter.ToInt32(_outBuff, _outputHeaderLen)) &&
-                          _outputPacketNumber == 1)
-                          ||
-                          (_outBytesUsed == _outputHeaderLen && _outputPacketNumber == 1),
-                          "SetPacketSize called with data in the buffer!");
-
-            if (_inBuff == null || _inBuff.Length != size)
-            { // We only check _inBuff, since two buffers should be consistent.
-                // Allocate or re-allocate _inBuff.
-                if (_inBuff == null)
-                {
-                    _inBuff = new byte[size];
-                    _inBytesRead = 0;
-                    _inBytesUsed = 0;
-                }
-                else if (size != _inBuff.Length)
-                {
-                    // If new size is other than existing...
-                    if (_inBytesRead > _inBytesUsed)
-                    {
-                        // if we still have data left in the buffer we must keep that array reference and then copy into new one
-                        byte[] temp = _inBuff;
-
-                        _inBuff = new byte[size];
-
-                        // copy remainder of unused data
-                        int remainingData = _inBytesRead - _inBytesUsed;
-                        if ((temp.Length < _inBytesUsed + remainingData) || (_inBuff.Length < remainingData))
-                        {
-                            string errormessage = StringsHelper.GetString(Strings.SQL_InvalidInternalPacketSize) + ' ' + temp.Length + ", " + _inBytesUsed + ", " + remainingData + ", " + _inBuff.Length;
-                            throw SQL.InvalidInternalPacketSize(errormessage);
-                        }
-                        Buffer.BlockCopy(temp, _inBytesUsed, _inBuff, 0, remainingData);
-
-                        _inBytesRead = _inBytesRead - _inBytesUsed;
-                        _inBytesUsed = 0;
-
-                        AssertValidState();
-                    }
-                    else
-                    {
-                        // buffer is empty - just create the new one that is double the size of the old one
-                        _inBuff = new byte[size];
-                        _inBytesRead = 0;
-                        _inBytesUsed = 0;
-                    }
-                }
-
-                // Always re-allocate _outBuff - assert is above to verify state.
-                _outBuff = new byte[size];
-                _outBytesUsed = _outputHeaderLen;
-
-                AssertValidState();
-                return true;
-            }
-
-            return false;
-        }
-
         ///////////////////////////////////////
         // Buffer read methods - data values //
         ///////////////////////////////////////
@@ -1361,7 +368,7 @@ public bool TryReadByteArray(Span<byte> buff, int len, out int totalRead)
                 _networkPacketTaskSource = new TaskCompletionSource<object>();
                 Interlocked.MemoryBarrier();
 
-                if (_forcePendingReadsToWaitForUser)
+                if (s_forcePendingReadsToWaitForUser)
                 {
                     _realNetworkPacketTaskSource = new TaskCompletionSource<object>();
                     _realNetworkPacketTaskSource.SetResult(null);
@@ -1391,7 +398,7 @@ public bool TryReadByteArray(Span<byte> buff, int len, out int totalRead)
                 Debug.Assert(bytesToRead > 0, "0 byte read in TryReadByteArray");
                 if (!buff.IsEmpty)
                 {
-                    var copyFrom = new ReadOnlySpan<byte>(_inBuff, _inBytesUsed, bytesToRead);
+                    ReadOnlySpan<byte> copyFrom = new ReadOnlySpan<byte>(_inBuff, _inBytesUsed, bytesToRead);
                     Span<byte> copyTo = buff.Slice(totalRead, bytesToRead);
                     copyFrom.CopyTo(copyTo);
                 }
@@ -1420,7 +427,7 @@ internal bool TryReadByte(out byte value)
                 _networkPacketTaskSource = new TaskCompletionSource<object>();
                 Interlocked.MemoryBarrier();
 
-                if (_forcePendingReadsToWaitForUser)
+                if (s_forcePendingReadsToWaitForUser)
                 {
                     _realNetworkPacketTaskSource = new TaskCompletionSource<object>();
                     _realNetworkPacketTaskSource.SetResult(null);
@@ -1557,7 +564,7 @@ internal bool TryReadInt64(out long value)
                 // If the long isn't fully in the buffer, or if it isn't fully in the packet,
                 // then use ReadByteArray since the logic is there to take care of that.
 
-                int bytesRead = 0;
+                int bytesRead;
                 if (!TryReadByteArray(_bTmp.AsSpan(_bTmpRead), 8 - _bTmpRead, out bytesRead))
                 {
                     Debug.Assert(_bTmpRead + bytesRead <= 8, "Read more data than required");
@@ -1635,7 +642,7 @@ internal bool TryReadUInt32(out uint value)
                 // If the int isn't fully in the buffer, or if it isn't fully in the packet,
                 // then use ReadByteArray since the logic is there to take care of that.
 
-                int bytesRead = 0;
+                int bytesRead;
                 if (!TryReadByteArray(_bTmp.AsSpan(_bTmpRead), 4 - _bTmpRead, out bytesRead))
                 {
                     Debug.Assert(_bTmpRead + bytesRead <= 4, "Read more data than required");
@@ -1677,7 +684,7 @@ internal bool TryReadSingle(out float value)
 
                 if (!TryReadByteArray(_bTmp, 4))
                 {
-                    value = default(float);
+                    value = default;
                     return false;
                 }
 
@@ -1782,8 +789,7 @@ internal bool TryReadStringWithEncoding(int length, System.Text.Encoding encodin
                 // Need to skip the current column before throwing the error - this ensures that the state shared between this and the data reader is consistent when calling DrainData
                 if (isPlp)
                 {
-                    ulong ignored;
-                    if (!_parser.TrySkipPlpValue((ulong)length, this, out ignored))
+                    if (!_parser.TrySkipPlpValue((ulong)length, this, out _))
                     {
                         value = null;
                         return false;
@@ -1910,7 +916,7 @@ internal bool TryReadPlpLength(bool returnPlpNullIfNull, out ulong lengthLeft)
                 }
                 else
                 {
-                    _longlenleft = (ulong)chunklen;
+                    _longlenleft = chunklen;
                 }
             }
 
@@ -1953,7 +959,6 @@ internal bool TryReadPlpBytes(ref byte[] buff, int offset, int len, out int tota
             int bytesRead;
             int bytesLeft;
             byte[] newbuf;
-            ulong ignored;
 
             if (_longlen == 0)
             {
@@ -1987,13 +992,13 @@ internal bool TryReadPlpBytes(ref byte[] buff, int offset, int len, out int tota
                 if ((ulong)(buff?.Length ?? 0) != _longlen)
                 {
                     // if the buffer is null or the wrong length create one to use
-                    buff = new byte[(int)Math.Min((int)_longlen, len)];
+                    buff = new byte[(Math.Min((int)_longlen, len))];
                 }
             }
 
             if (_longlenleft == 0)
             {
-                if (!TryReadPlpLength(false, out ignored))
+                if (!TryReadPlpLength(false, out _))
                 {
                     totalBytesRead = 0;
                     return false;
@@ -2045,7 +1050,7 @@ internal bool TryReadPlpBytes(ref byte[] buff, int offset, int len, out int tota
                 if (_longlenleft == 0)
                 {
                     // Read the next chunk or cleanup state if hit the end
-                    if (!TryReadPlpLength(false, out ignored))
+                    if (!TryReadPlpLength(false, out _))
                     {
                         if (_snapshot != null)
                         {
@@ -2078,16 +1083,15 @@ internal bool TryReadPlpBytes(ref byte[] buff, int offset, int len, out int tota
         internal bool TrySkipLongBytes(long num)
         {
             Debug.Assert(_syncOverAsync || !_asyncReadWithoutSnapshot, "This method is not safe to call when doing sync over async");
-            int cbSkip = 0;
 
             while (num > 0)
             {
-                cbSkip = (int)Math.Min((long)int.MaxValue, num);
+                int cbSkip = (int)Math.Min(int.MaxValue, num);
                 if (!TryReadByteArray(Span<byte>.Empty, cbSkip))
                 {
                     return false;
                 }
-                num -= (long)cbSkip;
+                num -= cbSkip;
             }
 
             return true;
@@ -2149,7 +1153,7 @@ internal bool TryReadNetworkPacket()
                     if (_snapshot.Replay())
                     {
 #if DEBUG
-                        if (_checkNetworkPacketRetryStacks)
+                        if (s_checkNetworkPacketRetryStacks)
                         {
                             _snapshot.CheckStack(Environment.StackTrace);
                         }
@@ -2159,7 +1163,7 @@ internal bool TryReadNetworkPacket()
 #if DEBUG
                     else
                     {
-                        if (_checkNetworkPacketRetryStacks)
+                        if (s_checkNetworkPacketRetryStacks)
                         {
                             _lastStack = Environment.StackTrace;
                         }
@@ -2180,11 +1184,11 @@ internal bool TryReadNetworkPacket()
             ReadSni(new TaskCompletionSource<object>());
 
 #if DEBUG
-            if (_failAsyncPends)
+            if (s_failAsyncPends)
             {
                 throw new InvalidOperationException("Attempted to pend a read when _failAsyncPends test hook was enabled");
             }
-            if (_forceSyncOverAsyncAfterFirstPend)
+            if (s_forceSyncOverAsyncAfterFirstPend)
             {
                 _syncOverAsync = true;
             }
@@ -2234,7 +1238,7 @@ internal void ReadSniSyncOverAsync()
 
                     ProcessSniPacket(readPacket, 0);
 #if DEBUG
-                    if (_forcePendingReadsToWaitForUser)
+                    if (s_forcePendingReadsToWaitForUser)
                     {
                         _networkPacketTaskSource = new TaskCompletionSource<object>();
                         Interlocked.MemoryBarrier();
@@ -2288,7 +1292,7 @@ internal void OnConnectionClosed()
             Interlocked.MemoryBarrier();
 
             // then check for networkPacketTaskSource
-            var taskSource = _networkPacketTaskSource;
+            TaskCompletionSource<object> taskSource = _networkPacketTaskSource;
             if (taskSource != null)
             {
                 taskSource.TrySetException(ADP.ExceptionWithStackTrace(ADP.ClosedConnectionError()));
@@ -2363,7 +1367,7 @@ private bool OnTimeoutCore(int expectedState, int targetState, bool asyncClose =
                 {
                     if (!_attentionSent)
                     {
-                        AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, (byte)0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
+                        AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, 0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
 
                         // Grab a reference to the _networkPacketTaskSource in case it becomes null while we are trying to use it
                         TaskCompletionSource<object> source = _networkPacketTaskSource;
@@ -2474,7 +1478,7 @@ internal void ReadSni(TaskCompletionSource<object> completion)
             }
 
 #if DEBUG
-            if (_forcePendingReadsToWaitForUser)
+            if (s_forcePendingReadsToWaitForUser)
             {
                 _realNetworkPacketTaskSource = new TaskCompletionSource<object>();
             }
@@ -2508,7 +1512,7 @@ internal void ReadSni(TaskCompletionSource<object> completion)
                     Timeout.Infinite,
                     Timeout.Infinite
                 );
-
+                
 
                 // -1 == Infinite
                 //  0 == Already timed out (NOTE: To simulate the same behavior as sync we will only timeout on 0 if we receive an IO Pending from SNI)
@@ -2559,7 +1563,7 @@ internal void ReadSni(TaskCompletionSource<object> completion)
 
                     ReadSniError(this, error);
 #if DEBUG
-                    if ((_forcePendingReadsToWaitForUser) && (_realNetworkPacketTaskSource != null))
+                    if ((s_forcePendingReadsToWaitForUser) && (_realNetworkPacketTaskSource != null))
                     {
                         _realNetworkPacketTaskSource.TrySetResult(null);
                     }
@@ -2700,7 +1704,7 @@ private void ReadSniError(TdsParserStateObject stateObj, uint error)
                 {
                     stateObj.SetTimeoutStateStopped();
                     Debug.Assert(_parser.Connection != null, "SqlConnectionInternalTds handler can not be null at this point.");
-                    AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, (byte)0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
+                    AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, 0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
 
                     if (!stateObj._attentionSent)
                     {
@@ -2897,7 +1901,7 @@ public void ReadAsyncCallback(IntPtr key, PacketHandle packet, uint error)
 
             TaskCompletionSource<object> source = _networkPacketTaskSource;
 #if DEBUG
-            if ((_forcePendingReadsToWaitForUser) && (_realNetworkPacketTaskSource != null))
+            if ((s_forcePendingReadsToWaitForUser) && (_realNetworkPacketTaskSource != null))
             {
                 source = _realNetworkPacketTaskSource;
             }
@@ -2916,7 +1920,7 @@ public void ReadAsyncCallback(IntPtr key, PacketHandle packet, uint error)
                 Debug.Assert(CheckPacket(packet, source) && source != null, "AsyncResult null on callback");
 
                 if (_parser.MARSOn)
-                {
+                { 
                     // Only take reset lock on MARS and Async.
                     CheckSetResetConnectionState(error, CallbackType.Read);
                 }
@@ -3051,7 +2055,7 @@ public void WriteAsyncCallback(IntPtr key, PacketHandle packet, uint sniError)
                     }
                     catch (Exception e)
                     {
-                        var writeCompletionSource = _writeCompletionSource;
+                        TaskCompletionSource<object> writeCompletionSource = _writeCompletionSource;
                         if (writeCompletionSource != null)
                         {
                             writeCompletionSource.TrySetException(e);
@@ -3067,7 +2071,7 @@ public void WriteAsyncCallback(IntPtr key, PacketHandle packet, uint sniError)
                             writeCompletionSource = _writeCompletionSource;
                             if (writeCompletionSource != null)
                             {
-                                var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
+                                Exception delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
                                 if (delayedException != null)
                                 {
                                     writeCompletionSource.TrySetException(delayedException);
@@ -3091,7 +2095,7 @@ public void WriteAsyncCallback(IntPtr key, PacketHandle packet, uint sniError)
                     new Timer(obj =>
                     {
                         Interlocked.Decrement(ref _asyncWriteCount);
-                        var writeCompletionSource = _writeCompletionSource;
+                        TaskCompletionSource<object> writeCompletionSource = _writeCompletionSource;
                         if (_asyncWriteCount == 0 && writeCompletionSource != null)
                         {
                             writeCompletionSource.TrySetResult(null);
@@ -3112,7 +2116,7 @@ public void WriteAsyncCallback(IntPtr key, PacketHandle packet, uint sniError)
                 return;
             }
 #endif
-            var completionSource = _writeCompletionSource;
+            TaskCompletionSource<object> completionSource = _writeCompletionSource;
             if (_asyncWriteCount == 0 && completionSource != null)
             {
                 completionSource.TrySetResult(null);
@@ -3154,7 +2158,7 @@ internal void ResetSecurePasswordsInformation()
         internal Task WaitForAccumulatedWrites()
         {
             // Checked for stored exceptions
-            var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
+            Exception delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
             if (delayedException != null)
             {
                 throw delayedException;
@@ -3445,7 +2449,7 @@ private void CancelWritePacket()
         private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccumulate, bool callerHasConnectionLock, bool asyncClose = false)
         {
             // Check for a stored exception
-            var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
+            Exception delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
             if (delayedException != null)
             {
                 throw delayedException;
@@ -3603,7 +2607,7 @@ internal void SendAttention(bool mustTakeWriteLock = false, bool asyncClose = fa
                     // This prevents a race condition between receiving the attention ACK and setting _attentionSent
                     _attentionSending = true;
 #if DEBUG
-                    if (!_skipSendAttention)
+                    if (!s_skipSendAttention)
                     {
 #endif
                         // Take lock and send attention
@@ -3636,7 +2640,7 @@ internal void SendAttention(bool mustTakeWriteLock = false, bool asyncClose = fa
                             }
                         }
 #if DEBUG
-                    }
+                }
 #endif
 
                     SetTimeoutSeconds(AttentionTimeoutSeconds); // Initialize new attention timeout of 5 seconds.
@@ -3666,9 +2670,8 @@ private Task WriteSni(bool canAccumulate)
             SetBufferSecureStrings();
             SetPacketData(packet, _outBuff, _outBytesUsed);
 
-            uint sniError;
             Debug.Assert(Parser.Connection._parserLock.ThreadMayHaveLock(), "Thread is writing without taking the connection lock");
-            Task task = SNIWritePacket(packet, out sniError, canAccumulate, callerHasConnectionLock: true);
+            Task task = SNIWritePacket(packet, out _, canAccumulate, callerHasConnectionLock: true);
 
             // Check to see if the timeout has occurred.  This time out code is special case code to allow BCP writes to timeout. Eventually we should make all writes timeout.
             if (_bulkCopyOpperationInProgress && 0 == GetTimeoutRemaining())
@@ -3677,7 +2680,7 @@ private Task WriteSni(bool canAccumulate)
                 try
                 {
                     Debug.Assert(_parser.Connection != null, "SqlConnectionInternalTds handler can not be null at this point.");
-                    AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, (byte)0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
+                    AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, 0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
                     _bulkCopyWriteTimeout = true;
                     SendAttention();
                     _parser.ProcessPendingAck(this);
@@ -3861,7 +2864,6 @@ internal int WarningCount
         }
 
         protected abstract PacketHandle EmptyReadPacket { get; }
-        internal int ObjectID => _objectID;
 
         internal int PreAttentionErrorCount
         {
@@ -3996,7 +2998,7 @@ internal void CheckThrowSNIException()
         internal void AssertStateIsClean()
         {
             // If our TdsParser is closed or broken, then we don't really care about our state
-            var parser = _parser;
+            TdsParser parser = _parser;
             if ((parser != null) && (parser.State != TdsParserState.Closed) && (parser.State != TdsParserState.Broken))
             {
                 // Async reads
@@ -4018,10 +3020,10 @@ internal void AssertStateIsClean()
 #if DEBUG
         internal void CompletePendingReadWithSuccess(bool resetForcePendingReadsToWait)
         {
-            var realNetworkPacketTaskSource = _realNetworkPacketTaskSource;
-            var networkPacketTaskSource = _networkPacketTaskSource;
+            TaskCompletionSource<object> realNetworkPacketTaskSource = _realNetworkPacketTaskSource;
+            TaskCompletionSource<object> networkPacketTaskSource = _networkPacketTaskSource;
 
-            Debug.Assert(_forcePendingReadsToWaitForUser, "Not forcing pends to wait for user - can't force complete");
+            Debug.Assert(s_forcePendingReadsToWaitForUser, "Not forcing pends to wait for user - can't force complete");
             Debug.Assert(networkPacketTaskSource != null, "No pending read to complete");
 
             try
@@ -4038,7 +3040,7 @@ internal void CompletePendingReadWithSuccess(bool resetForcePendingReadsToWait)
                 {
                     if (resetForcePendingReadsToWait)
                     {
-                        _forcePendingReadsToWaitForUser = false;
+                        s_forcePendingReadsToWaitForUser = false;
                     }
 
                     networkPacketTaskSource.TrySetResult(null);
@@ -4048,10 +3050,10 @@ internal void CompletePendingReadWithSuccess(bool resetForcePendingReadsToWait)
 
         internal void CompletePendingReadWithFailure(int errorCode, bool resetForcePendingReadsToWait)
         {
-            var realNetworkPacketTaskSource = _realNetworkPacketTaskSource;
-            var networkPacketTaskSource = _networkPacketTaskSource;
+            TaskCompletionSource<object> realNetworkPacketTaskSource = _realNetworkPacketTaskSource;
+            TaskCompletionSource<object> networkPacketTaskSource = _networkPacketTaskSource;
 
-            Debug.Assert(_forcePendingReadsToWaitForUser, "Not forcing pends to wait for user - can't force complete");
+            Debug.Assert(s_forcePendingReadsToWaitForUser, "Not forcing pends to wait for user - can't force complete");
             Debug.Assert(networkPacketTaskSource != null, "No pending read to complete");
 
             try
@@ -4068,7 +3070,7 @@ internal void CompletePendingReadWithFailure(int errorCode, bool resetForcePendi
                 {
                     if (resetForcePendingReadsToWait)
                     {
-                        _forcePendingReadsToWaitForUser = false;
+                        s_forcePendingReadsToWaitForUser = false;
                     }
 
                     AddError(new SqlError(errorCode, 0x00, TdsEnums.FATAL_ERROR_CLASS, _parser.Server, string.Empty, string.Empty, 0));
@@ -4162,7 +3164,7 @@ partial void SetStackInternal(string value)
 #if DEBUG
             internal bool DoPend()
             {
-                if (_failAsyncPends || !_forceAllPends)
+                if (s_failAsyncPends || !s_forceAllPends)
                 {
                     return false;
                 }
@@ -4364,43 +3366,5 @@ internal void Clear()
                 _sparePacket = packet;
             }
         }
-
-        /*
-
-        // leave this in. comes handy if you have to do Console.WriteLine style debugging ;)
-                private void DumpBuffer() {
-                    Console.WriteLine("dumping buffer");
-                    Console.WriteLine("_inBytesRead = {0}", _inBytesRead);
-                    Console.WriteLine("_inBytesUsed = {0}", _inBytesUsed);
-                    int cc = 0; // character counter
-                    int i;
-                    Console.WriteLine("used buffer:");
-                    for (i=0; i< _inBytesUsed; i++) {
-                        if (cc==16) {
-                            Console.WriteLine();
-                            cc = 0;
-                        }
-                        Console.Write("{0,-2:X2} ", _inBuff[i]);
-                        cc++;
-                    }
-                    if (cc>0) {
-                        Console.WriteLine();
-                    }
-
-                    cc = 0;
-                    Console.WriteLine("unused buffer:");
-                    for (i=_inBytesUsed; i<_inBytesRead; i++) {
-                        if (cc==16) {
-                            Console.WriteLine();
-                            cc = 0;
-                        }
-                        Console.Write("{0,-2:X2} ", _inBuff[i]);
-                        cc++;
-                    }
-                    if (cc>0) {
-                        Console.WriteLine();
-                    }
-                }
-        */
     }
 }
diff --git a/src/Microsoft.Data.SqlClient/netfx/src/Microsoft.Data.SqlClient.csproj b/src/Microsoft.Data.SqlClient/netfx/src/Microsoft.Data.SqlClient.csproj
index ff5b7e3c63..87058e31d0 100644
--- a/src/Microsoft.Data.SqlClient/netfx/src/Microsoft.Data.SqlClient.csproj
+++ b/src/Microsoft.Data.SqlClient/netfx/src/Microsoft.Data.SqlClient.csproj
@@ -563,6 +563,9 @@
     <Compile Include="..\..\src\Microsoft\Data\SqlClient\TdsParserSafeHandles.Windows.cs">
       <Link>Microsoft\Data\SqlClient\TdsParserSafeHandles.Windows.cs</Link>
     </Compile>
+    <Compile Include="..\..\src\Microsoft\Data\SqlClient\TdsParserStateObject.cs">
+      <Link>Microsoft\Data\SqlClient\TdsParserStateObject.cs</Link>
+    </Compile>
     <Compile Include="..\..\src\Microsoft\Data\SqlClient\TdsParserStaticMethods.cs">
       <Link>Microsoft\Data\SqlClient\TdsParserStaticMethods.cs</Link>
     </Compile>
diff --git a/src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlUtil.cs b/src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlUtil.cs
index 4cd10a988b..621d47b20f 100644
--- a/src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlUtil.cs
+++ b/src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlUtil.cs
@@ -46,6 +46,28 @@ internal static Task CreateContinuationTask(Task task, Action onSuccess, SqlInte
             }
         }
 
+        internal static Task CreateContinuationTaskWithState(Task task, object state, Action<object> onSuccess, Action<Exception, object> onFailure = null)
+        {
+            if (task == null)
+            {
+                onSuccess(state);
+                return null;
+            }
+            else
+            {
+                TaskCompletionSource<object> completion = new();
+                ContinueTaskWithState(task, completion, state,
+                    onSuccess: (object continueState) =>
+                    {
+                        onSuccess(continueState);
+                        completion.SetResult(null);
+                    },
+                    onFailure: onFailure
+                );
+                return completion.Task;
+            }
+        }
+
         internal static Task CreateContinuationTask<T1, T2>(Task task, Action<T1, T2> onSuccess, T1 arg1, T2 arg2, SqlInternalConnectionTds connectionToDoom = null, Action<Exception> onFailure = null)
         {
             return CreateContinuationTask(task, () => onSuccess(arg1, arg2), connectionToDoom, onFailure);
diff --git a/src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs b/src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
index 8d9057bc02..99d303af3e 100644
--- a/src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
+++ b/src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
@@ -10,150 +10,30 @@
 using System.Runtime.ConstrainedExecution;
 using System.Runtime.InteropServices;
 using System.Security;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Data.Common;
 
 namespace Microsoft.Data.SqlClient
 {
-    sealed internal class LastIOTimer
+    internal partial class TdsParserStateObject
     {
-        internal long _value;
-    }
-
-    sealed internal class TdsParserStateObject
-    {
-        private const int AttentionTimeoutSeconds = 5;
-
-        // Ticks to consider a connection "good" after a successful I/O (10,000 ticks = 1 ms)
-        // The resolution of the timer is typically in the range 10 to 16 milliseconds according to msdn.
-        // We choose a value that is smaller than the likely timer resolution, but
-        // large enough to ensure that check connection execution will be 0.1% or less
-        // of very small open, query, close loops.
-        private const long CheckConnectionWindow = 50000;
-
-        private sealed class TimeoutState
-        {
-            public const int Stopped = 0;
-            public const int Running = 1;
-            public const int ExpiredAsync = 2;
-            public const int ExpiredSync = 3;
-
-            private readonly int _value;
-
-            public TimeoutState(int value)
-            {
-                _value = value;
-            }
-
-            public int IdentityValue => _value;
-        }
-
-        private static int _objectTypeCount; // EventSource Counter
-        internal readonly int _objectID = System.Threading.Interlocked.Increment(ref _objectTypeCount);
-
-        internal int ObjectID
-        {
-            get
-            {
-                return _objectID;
-            }
-        }
-
-        private readonly TdsParser _parser;                            // TdsParser pointer  
         private SNIHandle _sessionHandle = null;              // the SNI handle we're to work on
-        private readonly WeakReference<object> _owner = new WeakReference<object>(null);   // the owner of this session, used to track when it's been orphaned
-        internal SqlDataReader.SharedState _readerState;                    // susbset of SqlDataReader state (if it is the owner) necessary for parsing abandoned results in TDS
-        private int _activateCount;                     // 0 when we're in the pool, 1 when we're not, all others are an error
-
-        // Two buffers exist in tdsparser, an in buffer and an out buffer.  For the out buffer, only
-        // one bookkeeping variable is needed, the number of bytes used in the buffer.  For the in buffer,
-        // three variables are actually needed.  First, we need to record from the netlib how many bytes it
-        // read from the netlib, this variable is _inBytesRead.  Then, we need to also keep track of how many
-        // bytes we have used as we consume the bytes from the buffer, that variable is _inBytesUsed.  Third,
-        // we need to keep track of how many bytes are left in the packet, so that we know when we have reached
-        // the end of the packet and so we need to consume the next header.  That variable is _inBytesPacket.
-
-        // Header length constants
-        internal readonly int _inputHeaderLen = TdsEnums.HEADER_LEN;
-        internal readonly int _outputHeaderLen = TdsEnums.HEADER_LEN;
-
-        // Out buffer variables
-        internal byte[] _outBuff;                                     // internal write buffer - initialize on login
-        internal int _outBytesUsed = TdsEnums.HEADER_LEN; // number of bytes used in internal write buffer -
-                                                          // - initialize past header
-                                                          // In buffer variables
-        private byte[] _inBuff;                                      // internal read buffer - initialize on login
-        internal int _inBytesUsed = 0;                   // number of bytes used in internal read buffer
-        internal int _inBytesRead = 0;                   // number of bytes read into internal read buffer
-        internal int _inBytesPacket = 0;                   // number of bytes left in packet
-        internal int _spid;                                 // SPID of the current connection
-
-        // Packet state variables
-        internal byte _outputMessageType = 0;                   // tds header type
-        internal byte _messageStatus;                               // tds header status
-        internal byte _outputPacketNumber = 1;                   // number of packets sent to server in message - start at 1 per ramas
-        internal uint _outputPacketCount;
-        internal bool _pendingData = false;
-        internal volatile bool _fResetEventOwned = false;               // ResetEvent serializing call to sp_reset_connection
-        internal volatile bool _fResetConnectionSent = false;               // For multiple packet execute
 
+        internal bool _pendingData = false;
         internal bool _errorTokenReceived = false;               // Keep track of whether an error was received for the result.
                                                                  // This is reset upon each done token - there can be
-
-        internal bool _bulkCopyOpperationInProgress = false;        // Set to true during bulk copy and used to turn toggle write timeouts.
-        internal bool _bulkCopyWriteTimeout = false;                // Set to trun when _bulkCopyOpeperationInProgress is trun and write timeout happens
-
         // SNI variables                                                     // multiple resultsets in one batch.
         private SNIPacket _sniPacket = null;                // Will have to re-vamp this for MARS
         internal SNIPacket _sniAsyncAttnPacket = null;                // Packet to use to send Attn
-        private WritePacketCache _writePacketCache = new WritePacketCache(); // Store write packets that are ready to be re-used
-        private Dictionary<IntPtr, SNIPacket> _pendingWritePackets = new Dictionary<IntPtr, SNIPacket>(); // Stores write packets that have been sent to SNI, but have not yet finished writing (i.e. we are waiting for SNI's callback)
-        private object _writePacketLockObject = new object();        // Used to synchronize access to _writePacketCache and _pendingWritePackets
+        private readonly WritePacketCache _writePacketCache = new WritePacketCache(); // Store write packets that are ready to be re-used
+        private readonly Dictionary<IntPtr, SNIPacket> _pendingWritePackets = new Dictionary<IntPtr, SNIPacket>(); // Stores write packets that have been sent to SNI, but have not yet finished writing (i.e. we are waiting for SNI's callback)
 
         // Async variables
         private GCHandle _gcHandle;                                    // keeps this object alive until we're closed.
-        private int _pendingCallbacks;                            // we increment this before each async read/write call and decrement it in the callback.  We use this to determine when to release the GcHandle...
 
         // Timeout variables
-        private long _timeoutMilliseconds;
-        private long _timeoutTime;                                 // variable used for timeout computations, holds the value of the hi-res performance counter at which this request should expire
-        private int _timeoutState; // expected to be one of the constant values TimeoutStopped, TimeoutRunning, TimeoutExpiredAsync, TimeoutExpiredSync
-        private int _timeoutIdentitySource;
-        private volatile int _timeoutIdentityValue;
-        internal volatile bool _attentionSent = false;               // true if we sent an Attention to the server
         internal bool _attentionReceived = false;               // NOTE: Received is not volatile as it is only ever accessed\modified by TryRun its callees (i.e. single threaded access)
-        internal volatile bool _attentionSending = false;
-
-        // Below 2 properties are used to enforce timeout delays in code to 
-        // reproduce issues related to theadpool starvation and timeout delay.
-        // It should always be set to false by default, and only be enabled during testing.
-        internal bool _enforceTimeoutDelay = false;
-        internal int _enforcedTimeoutDelayInMilliSeconds = 5000;
-
-        private readonly LastIOTimer _lastSuccessfulIOTimer;
-
-        // secure password information to be stored
-        //  At maximum number of secure string that need to be stored is two; one for login password and the other for new change password
-        private SecureString[] _securePasswords = new SecureString[2] { null, null };
-        private int[] _securePasswordOffsetsInBuffer = new int[2];
-
-        // This variable is used to track whether another thread has requested a cancel.  The
-        // synchronization points are
-        //   On the user's execute thread:
-        //     1) the first packet write
-        //     2) session close - return this stateObj to the session pool
-        //   On cancel thread we only have the cancel call.
-        // Currently all access to this variable is inside a lock, though I hope to limit that in the
-        // future.  The state diagram is:
-        // 1) pre first packet write, if cancel is requested, set variable so exception is triggered
-        //    on user thread when first packet write is attempted
-        // 2) post first packet write, but before session return - a call to cancel will send an
-        //    attention to the server
-        // 3) post session close - no attention is allowed
-        private bool _cancelled;
-        private const int _waitForCancellationLockPollTimeout = 100;
 
         // This variable is used to prevent sending an attention by another thread that is not the
         // current owner of the stateObj.  I currently do not know how this can happen.  Mark added
@@ -162,33 +42,6 @@ internal int ObjectID
         private volatile int _allowObjectID;
 
         internal bool _hasOpenResult = false;
-        // Cache the transaction for which this command was executed so upon completion we can
-        // decrement the appropriate result count.
-        internal SqlInternalTransaction _executedUnderTransaction = null;
-
-        // TDS stream processing variables
-        internal ulong _longlen;                                     // plp data length indicator
-        internal ulong _longlenleft;                                 // Length of data left to read (64 bit lengths)
-        internal int[] _decimalBits = null;                // scratch buffer for decimal/numeric data
-        internal byte[] _bTmp = new byte[TdsEnums.SQL2005_HEADER_LEN];  // Scratch buffer for misc use
-        internal int _bTmpRead = 0;                   // Counter for number of temporary bytes read
-        internal Decoder _plpdecoder = null;             // Decoder object to process plp character data
-        internal bool _accumulateInfoEvents = false;               // TRUE - accumulate info messages during TdsParser.Run, FALSE - fire them
-        internal List<SqlError> _pendingInfoEvents = null;
-        internal byte[] _bLongBytes = null;                 // scratch buffer to serialize Long values (8 bytes).
-        internal byte[] _bIntBytes = null;                 // scratch buffer to serialize Int values (4 bytes).
-        internal byte[] _bShortBytes = null;                 // scratch buffer to serialize Short values (2 bytes).
-        internal byte[] _bDecimalBytes = null;                 // scratch buffer to serialize decimal values (17 bytes).
-
-        // DO NOT USE THIS BUFFER FOR OTHER THINGS.
-        // ProcessHeader can be called ANYTIME while doing network reads.
-        private byte[] _partialHeaderBuffer = new byte[TdsEnums.HEADER_LEN];   // Scratch buffer for ProcessHeader
-        internal int _partialHeaderBytesRead = 0;
-
-        // UNDONE - temporary hack for case where pooled connection is returned to pool with data on wire -
-        // need to cache metadata on parser to read off wire
-        internal _SqlMetaDataSet _cleanupMetaData = null;
-        internal _SqlMetaDataSetCollection _cleanupAltMetaDataSetArray = null;
 
         // Used for blanking out password in trace.
         internal int _tracePasswordOffset = 0;
@@ -198,112 +51,10 @@ internal int ObjectID
 
         internal bool _receivedColMetaData;      // Used to keep track of when to fire StatementCompleted  event.
 
-        private SniContext _sniContext = SniContext.Undefined;
-#if DEBUG
-        private SniContext _debugOnlyCopyOfSniContext = SniContext.Undefined;
-#endif
-
-        private bool _bcpLock = false;
-
-        // Null bitmap compression (NBC) information for the current row
-        private NullBitmap _nullBitmapInfo;
-
-        // Async
-        internal TaskCompletionSource<object> _networkPacketTaskSource;
-        private Timer _networkPacketTimeout;
-        internal bool _syncOverAsync = true;
-        private bool _snapshotReplay = false;
-        private StateSnapshot _snapshot;
-        internal ExecutionContext _executionContext;
-        internal bool _asyncReadWithoutSnapshot = false;
-#if DEBUG
-        // Used to override the assert than ensures that the stacktraces on subsequent replays are the same
-        // This is useful is you are purposefully running the replay from a different thread (e.g. during SqlDataReader.Close)
-        internal bool _permitReplayStackTraceToDiffer = false;
-
-        // Used to indicate that the higher level object believes that this stateObj has enough data to complete an operation
-        // If this stateObj has to read, then it will raise an assert
-        internal bool _shouldHaveEnoughData = false;
-#endif
-
-        // local exceptions to cache warnings and errors
-        internal SqlErrorCollection _errors;
-        internal SqlErrorCollection _warnings;
-        internal object _errorAndWarningsLock = new object();
-        private bool _hasErrorOrWarning = false;
-
-        // local exceptions to cache warnings and errors that occurred prior to sending attention
-        internal SqlErrorCollection _preAttentionErrors;
-        internal SqlErrorCollection _preAttentionWarnings;
-
-        volatile private TaskCompletionSource<object> _writeCompletionSource = null;
-        volatile private int _asyncWriteCount = 0;
-        volatile private Exception _delayedWriteAsyncCallbackException = null; // set by write async callback if completion source is not yet created
-
-        // _readingcount is incremented when we are about to read.
-        // We check the parser state afterwards.
-        // When the read is completed, we decrement it before handling errors
-        // as the error handling may end up calling Dispose.
-        int _readingCount;
-
-        // Test hooks
-#if DEBUG
-        // This is a test hook to enable testing of the retry paths.
-        // When set to true, almost every possible retry point will be attempted.
-        // This will drastically impact performance.
-        //
-        // Sample code to enable:
-        //
-        //    Type type = typeof(SqlDataReader).Assembly.GetType("Microsoft.Data.SqlClient.TdsParserStateObject");
-        //    System.Reflection.FieldInfo field = type.GetField("_forceAllPends", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static);
-        //    if (field != null) {
-        //        field.SetValue(null, true);
-        //    }
-        //
-        internal static bool _forceAllPends = false;
-
-        // set this while making a call that should not block.
-        // instead of blocking it will fail.
-        internal static bool _failAsyncPends = false;
-
-        // If this is set and an async read is made, then 
-        // we will switch to syncOverAsync mode for the 
-        // remainder of the async operation.
-        internal static bool _forceSyncOverAsyncAfterFirstPend = false;
-
-        // Requests to send attention will be ignored when _skipSendAttention is true.
-        // This is useful to simulate circumstances where timeouts do not recover.
-        internal static bool _skipSendAttention = false;
-
-        // Prevents any pending read from completing until the user signals it using
-        // CompletePendingReadWithSuccess() or CompletePendingReadWithFailure(int errorCode) in SqlCommand\SqlDataReader
-        internal static bool _forcePendingReadsToWaitForUser;
-        internal TaskCompletionSource<object> _realNetworkPacketTaskSource = null;
-
-        // Set to true to enable checking the call stacks match when packet retry occurs.
-        internal static bool _checkNetworkPacketRetryStacks;
-#endif
-
         //////////////////
         // Constructors //
         //////////////////
 
-        internal TdsParserStateObject(TdsParser parser)
-        {
-            // Construct a physical connection
-            Debug.Assert(null != parser, "no parser?");
-            _parser = parser;
-
-            // For physical connection, initialize to default login packet size.
-            SetPacketSize(TdsEnums.DEFAULT_LOGIN_PACKET_SIZE);
-
-            // we post a callback that represents the call to dispose; once the
-            // object is disposed, the next callback will cause the GC Handle to
-            // be released.
-            IncrementPendingCallbacks();
-            _lastSuccessfulIOTimer = new LastIOTimer();
-        }
-
         internal TdsParserStateObject(TdsParser parser, SNIHandle physicalConnection, bool async)
         {
             // Construct a MARS session
@@ -322,7 +73,8 @@ internal TdsParserStateObject(TdsParser parser, SNIHandle physicalConnection, bo
 
             SNINativeMethodWrapper.ConsumerInfo myInfo = CreateConsumerInfo(async);
             SQLDNSInfo cachedDNSInfo;
-            bool ret = SQLFallbackDNSCache.Instance.GetDNSInfo(_parser.FQDNforDNSCache, out cachedDNSInfo);
+
+            SQLFallbackDNSCache.Instance.GetDNSInfo(_parser.FQDNforDNSCache, out cachedDNSInfo);
 
             _sessionHandle = new SNIHandle(myInfo, physicalConnection, _parser.Connection.ConnectionOptions.IPAddressPreference, cachedDNSInfo);
             if (_sessionHandle.Status != TdsEnums.SNI_SUCCESS)
@@ -341,31 +93,6 @@ internal TdsParserStateObject(TdsParser parser, SNIHandle physicalConnection, bo
         ////////////////
         // Properties //
         ////////////////
-
-        // BcpLock - use to lock this object if there is a potential risk of using this object
-        // between tds packets
-        internal bool BcpLock
-        {
-            get
-            {
-                return _bcpLock;
-            }
-            set
-            {
-                _bcpLock = value;
-            }
-        }
-
-#if DEBUG
-        internal SniContext DebugOnlyCopyOfSniContext
-        {
-            get
-            {
-                return _debugOnlyCopyOfSniContext;
-            }
-        }
-#endif
-
         internal SNIHandle Handle
         {
             get
@@ -376,74 +103,17 @@ internal SNIHandle Handle
 
         internal bool HasOpenResult
         {
-            get
-            {
-                return _hasOpenResult;
-            }
+            get => _hasOpenResult;
+            set => _hasOpenResult = value;
         }
-
-#if DEBUG
-        internal void InvalidateDebugOnlyCopyOfSniContext()
-        {
-            _debugOnlyCopyOfSniContext = SniContext.Undefined;
-        }
-#endif
-
-        internal bool IsOrphaned
-        {
-            get
-            {
-                bool isAlive = _owner.TryGetTarget(out object target);
-                Debug.Assert((0 == _activateCount && !isAlive) // in pool
-                             || (1 == _activateCount && isAlive && target != null)
-                             || (1 == _activateCount && !isAlive), "Unknown state on TdsParserStateObject.IsOrphaned!");
-                return 0 != _activateCount && !isAlive;
-            }
-        }
-
-        internal object Owner
-        {
-            set
-            {
-                Debug.Assert(value == null || !_owner.TryGetTarget(out object target) || value is SqlDataReader reader1 && reader1.Command == target, "Should not be changing the owner of an owned stateObj");
-                if (value is SqlDataReader reader)
-                {
-                    _readerState = reader._sharedState;
-                }
-                else
-                {
-                    _readerState = null;
-                }
-                _owner.SetTarget(value);
-            }
-        }
-
-        internal bool HasOwner => _owner.TryGetTarget(out object _);
-
-        internal TdsParser Parser
+        
+        internal bool HasPendingData
         {
-            get
-            {
-                return _parser;
-            }
+            get => _pendingData;
+            set => _pendingData = value;
         }
-
-        internal SniContext SniContext
-        {
-            get
-            {
-                return _sniContext;
-            }
-            set
-            {
-                _sniContext = value;
-#if DEBUG
-                _debugOnlyCopyOfSniContext = value;
-#endif
-            }
-        }
-
-        internal UInt32 Status
+        
+        internal uint Status
         {
             get
             {
@@ -458,112 +128,8 @@ internal UInt32 Status
             }
         }
 
-        internal bool TimeoutHasExpired
-        {
-            get
-            {
-                Debug.Assert(0 == _timeoutMilliseconds || 0 == _timeoutTime, "_timeoutTime hasn't been reset");
-                return TdsParserStaticMethods.TimeoutHasExpired(_timeoutTime);
-            }
-        }
-
-        internal long TimeoutTime
-        {
-            get
-            {
-                if (0 != _timeoutMilliseconds)
-                {
-                    _timeoutTime = TdsParserStaticMethods.GetTimeout(_timeoutMilliseconds);
-                    _timeoutMilliseconds = 0;
-                }
-                return _timeoutTime;
-            }
-            set
-            {
-                _timeoutMilliseconds = 0;
-                _timeoutTime = value;
-            }
-        }
-
-        internal int GetTimeoutRemaining()
-        {
-            int remaining;
-            if (0 != _timeoutMilliseconds)
-            {
-                remaining = (int)Math.Min((long)Int32.MaxValue, _timeoutMilliseconds);
-                _timeoutTime = TdsParserStaticMethods.GetTimeout(_timeoutMilliseconds);
-                _timeoutMilliseconds = 0;
-            }
-            else
-            {
-                remaining = TdsParserStaticMethods.GetTimeoutMilliseconds(_timeoutTime);
-            }
-            return remaining;
-        }
-
-        internal bool TryStartNewRow(bool isNullCompressed, int nullBitmapColumnsCount = 0)
-        {
-            Debug.Assert(!isNullCompressed || nullBitmapColumnsCount > 0, "Null-Compressed row requires columns count");
-
-            if (_snapshot != null)
-            {
-                _snapshot.CloneNullBitmapInfo();
-            }
-
-            // initialize or unset null bitmap information for the current row
-            if (isNullCompressed)
-            {
-                // assert that NBCROW is not in use by 2005 or before
-                Debug.Assert(_parser.Is2008OrNewer, "NBCROW is sent by pre-2008 server");
-
-                if (!_nullBitmapInfo.TryInitialize(this, nullBitmapColumnsCount))
-                {
-                    return false;
-                }
-            }
-            else
-            {
-                _nullBitmapInfo.Clean();
-            }
-
-            return true;
-        }
-
-        internal bool IsRowTokenReady()
-        {
-            // Removing one byte since TryReadByteArray\TryReadByte will aggressively read the next packet if there is no data left - so we need to ensure there is a spare byte
-            int bytesRemaining = Math.Min(_inBytesPacket, _inBytesRead - _inBytesUsed) - 1;
-
-            if (bytesRemaining > 0)
-            {
-                if (_inBuff[_inBytesUsed] == TdsEnums.SQLROW)
-                {
-                    // At a row token, so we're ready
-                    return true;
-                }
-                else if (_inBuff[_inBytesUsed] == TdsEnums.SQLNBCROW)
-                {
-                    // NBC row token, ensure that we have enough data for the bitmap
-                    // SQLNBCROW + Null Bitmap (copied from NullBitmap.TryInitialize)
-                    int bytesToRead = 1 + (_cleanupMetaData.Length + 7) / 8;
-                    return (bytesToRead <= bytesRemaining);
-                }
-            }
-
-            // No data left, or not at a row token
-            return false;
-        }
-
-        internal bool IsNullCompressionBitSet(int columnOrdinal)
+        private partial struct NullBitmap
         {
-            return _nullBitmapInfo.IsGuaranteedNull(columnOrdinal);
-        }
-
-        private struct NullBitmap
-        {
-            private byte[] _nullBitmap;
-            private int _columnsCount; // set to 0 if not used or > 0 for NBC rows
-
             internal bool TryInitialize(TdsParserStateObject stateObj, int columnsCount)
             {
                 _columnsCount = columnsCount;
@@ -587,61 +153,12 @@ internal bool TryInitialize(TdsParserStateObject stateObj, int columnsCount)
 
                 return true;
             }
-
-            internal bool ReferenceEquals(NullBitmap obj)
-            {
-                return object.ReferenceEquals(_nullBitmap, obj._nullBitmap);
-            }
-
-            internal NullBitmap Clone()
-            {
-                NullBitmap newBitmap = new NullBitmap();
-                newBitmap._nullBitmap = _nullBitmap == null ? null : (byte[])_nullBitmap.Clone();
-                newBitmap._columnsCount = _columnsCount;
-                return newBitmap;
-            }
-
-            internal void Clean()
-            {
-                _columnsCount = 0;
-                // no need to free _nullBitmap array - it is cached for the next row
-            }
-
-            /// <summary>
-            /// If this method returns true, the value is guaranteed to be null. This is not true vice versa: 
-            /// if the bitmat value is false (if this method returns false), the value can be either null or non-null - no guarantee in this case.
-            /// To determine whether it is null or not, read it from the TDS (per NBCROW design spec, for IMAGE/TEXT/NTEXT columns server might send
-            /// bitmap = 0, when the actual value is null).
-            /// </summary>
-            internal bool IsGuaranteedNull(int columnOrdinal)
-            {
-                if (_columnsCount == 0)
-                {
-                    // not an NBC row
-                    return false;
-                }
-
-                Debug.Assert(columnOrdinal >= 0 && columnOrdinal < _columnsCount, "Invalid column ordinal");
-
-                byte testBit = (byte)(1 << (columnOrdinal & 0x7)); // columnOrdinal & 0x7 == columnOrdinal MOD 0x7
-                byte testByte = _nullBitmap[columnOrdinal >> 3];
-                return (testBit & testByte) != 0;
-            }
         }
 
         /////////////////////
         // General methods //
         /////////////////////
 
-        // If this object is part of a TdsParserSessionPool, then this *must* be called inside the pool's lock
-        internal void Activate(object owner)
-        {
-            Debug.Assert(_parser.MARSOn, "Can not activate a non-MARS connection");
-            Owner = owner; // must assign an owner for reclaimation to work
-            int result = Interlocked.Increment(ref _activateCount);   // must have non-zero activation count for reclaimation to work too.
-            Debug.Assert(result == 1, "invalid deactivate count");
-        }
-
         // This method is only called by the command or datareader as a result of a user initiated
         // cancel request.
         internal void Cancel(int objectID)
@@ -653,7 +170,7 @@ internal void Cancel(int objectID)
                 while ((!hasLock) && (_parser.State != TdsParserState.Closed) && (_parser.State != TdsParserState.Broken))
                 {
 
-                    Monitor.TryEnter(this, _waitForCancellationLockPollTimeout, ref hasLock);
+                    Monitor.TryEnter(this, WaitForCancellationLockPollTimeout, ref hasLock);
                     if (hasLock)
                     { // Lock for the time being - since we need to synchronize the attention send.
                       // At some point in the future, I hope to remove this.
@@ -673,7 +190,7 @@ internal void Cancel(int objectID)
                                 {
                                     try
                                     {
-                                        _parser.Connection._parserLock.Wait(canReleaseFromAnyThread: false, timeout: _waitForCancellationLockPollTimeout, lockTaken: ref hasParserLock);
+                                        _parser.Connection._parserLock.Wait(canReleaseFromAnyThread: false, timeout: WaitForCancellationLockPollTimeout, lockTaken: ref hasParserLock);
                                         if (hasParserLock)
                                         {
                                             _parser.Connection.ThreadHasParserLockForClose = true;
@@ -706,88 +223,6 @@ internal void Cancel(int objectID)
             }
         }
 
-        // CancelRequest - use to cancel while writing a request to the server
-        //
-        // o none of the request might have been sent to the server, simply reset the buffer,
-        //   sending attention does not hurt
-        // o the request was partially written. Send an ignore header to the server. attention is
-        //   required if the server was waiting for data (e.g. insert bulk rows)
-        // o the request was completely written out and the server started to process the request.
-        //   attention is required to have the server stop processing.
-        //
-        internal void CancelRequest()
-        {
-            ResetBuffer();    // clear out unsent buffer
-            // VSDD#903514, if the first sqlbulkcopy timeout, _outputPacketNumber may not be 1, 
-            // the next sqlbulkcopy (same connection string) requires this to be 1, hence reset 
-            // it here when exception happens in the first sqlbulkcopy
-            ResetPacketCounters();
-
-            // VSDD#907507, if bulkcopy write timeout happens, it already sent the attention, 
-            // so no need to send it again
-            if (!_bulkCopyWriteTimeout)
-            {
-                SendAttention();
-                Parser.ProcessPendingAck(this);
-            }
-        }
-
-        public void CheckSetResetConnectionState(UInt32 error, CallbackType callbackType)
-        {
-            // Should only be called for MARS - that is the only time we need to take
-            // the ResetConnection lock!
-
-            // SQL BU DT 333026 - it was raised in a security review questioning whether
-            // we need to actually process the resulting packet (sp_reset ack or error) to know if the
-            // reset actually succeeded.  There was a concern that if the reset failed and we proceeded
-            // there might be a security issue present.  We have been assured by the server that if
-            // sp_reset fails, they guarantee they will kill the resulting connection.  So - it is
-            // safe for us to simply receive the packet and then consume the pre-login later.
-
-            Debug.Assert(_parser.MARSOn, "Should not be calling CheckSetResetConnectionState on non MARS connection");
-
-            if (_fResetEventOwned)
-            {
-                if (callbackType == CallbackType.Read && TdsEnums.SNI_SUCCESS == error)
-                {
-                    // RESET SUCCEEDED!
-                    // If we are on read callback and no error occurred (and we own reset event) -
-                    // then we sent the sp_reset_connection and so we need to reset sp_reset_connection
-                    // flag to false, and then release the ResetEvent.
-                    _parser._fResetConnection = false;
-                    _fResetConnectionSent = false;
-                    _fResetEventOwned = !_parser._resetConnectionEvent.Set();
-                    Debug.Assert(!_fResetEventOwned, "Invalid AutoResetEvent state!");
-                }
-
-                if (TdsEnums.SNI_SUCCESS != error)
-                {
-                    // RESET FAILED!
-
-                    // UNDONE - is there a bug here?
-                    // 1) Are there any cases where netlib write error does not mean reset was not executed?
-                    // 2) Can we receive error on 2nd or beyond packet write but the server has already
-                    // processed the reset???  I don't believe it is the case, but I have inserted a comment
-                    // here as a thought workitem.
-
-                    // If write or read failed with reset, we need to clear event but not mark connection
-                    // as reset.
-                    _fResetConnectionSent = false;
-                    _fResetEventOwned = !_parser._resetConnectionEvent.Set();
-                    Debug.Assert(!_fResetEventOwned, "Invalid AutoResetEvent state!");
-                }
-            }
-        }
-
-        internal void CloseSession()
-        {
-            ResetCancelAndProcessAttention();
-#if DEBUG
-            InvalidateDebugOnlyCopyOfSniContext();
-#endif
-            Parser.PutSession(this);
-        }
-
         private void ResetCancelAndProcessAttention()
         {
             // This method is shared by CloseSession initiated by DataReader.Close or completed
@@ -864,16 +299,16 @@ internal void CreatePhysicalSNIHandle(
 
             // Translate to SNI timeout values (Int32 milliseconds)
             long timeout;
-            if (Int64.MaxValue == timerExpire)
+            if (long.MaxValue == timerExpire)
             {
-                timeout = Int32.MaxValue;
+                timeout = int.MaxValue;
             }
             else
             {
                 timeout = ADP.TimerRemainingMilliseconds(timerExpire);
-                if (timeout > Int32.MaxValue)
+                if (timeout > int.MaxValue)
                 {
-                    timeout = Int32.MaxValue;
+                    timeout = int.MaxValue;
                 }
                 else if (0 > timeout)
                 {
@@ -891,69 +326,6 @@ internal void CreatePhysicalSNIHandle(
                 ipPreference, cachedDNSInfo, tlsFirst, hostNameInCertificate);
         }
 
-        internal bool Deactivate()
-        {
-            bool goodForReuse = false;
-
-            try
-            {
-                TdsParserState state = Parser.State;
-                if (state != TdsParserState.Broken && state != TdsParserState.Closed)
-                {
-                    if (_pendingData)
-                    {
-                        Parser.DrainData(this); // This may throw - taking us to catch block.
-                    }
-
-                    if (HasOpenResult)
-                    { // SQL BU DT 383773 - need to decrement openResultCount for all pending operations.
-                        DecrementOpenResultCount();
-                    }
-
-                    ResetCancelAndProcessAttention();
-                    goodForReuse = true;
-                }
-            }
-            catch (Exception e)
-            {
-                if (!ADP.IsCatchableExceptionType(e))
-                {
-                    throw;
-                }
-                ADP.TraceExceptionWithoutRethrow(e);
-            }
-            return goodForReuse;
-        }
-
-        // If this object is part of a TdsParserSessionPool, then this *must* be called inside the pool's lock
-        internal void RemoveOwner()
-        {
-            if (_parser.MARSOn)
-            {
-                // We only care about the activation count for MARS connections
-                int result = Interlocked.Decrement(ref _activateCount);   // must have non-zero activation count for reclaimation to work too.
-                Debug.Assert(result == 0, "invalid deactivate count");
-            }
-            Owner = null;
-        }
-
-        internal void DecrementOpenResultCount()
-        {
-            if (_executedUnderTransaction == null)
-            {
-                // If we were not executed under a transaction - decrement the global count
-                // on the parser.
-                _parser.DecrementNonTransactedOpenResultCount();
-            }
-            else
-            {
-                // If we were executed under a transaction - decrement the count on the transaction.
-                _executedUnderTransaction.DecrementAndObtainOpenResultCount();
-                _executedUnderTransaction = null;
-            }
-            _hasOpenResult = false;
-        }
-
         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
         internal int DecrementPendingCallbacks(bool release)
         {
@@ -982,25 +354,7 @@ internal void Dispose()
             _sessionHandle = null;
             _sniAsyncAttnPacket = null;
 
-            Timer networkPacketTimeout = _networkPacketTimeout;
-            if (networkPacketTimeout != null)
-            {
-                _networkPacketTimeout = null;
-                networkPacketTimeout.Dispose();
-            }
-
-            Debug.Assert(Volatile.Read(ref _readingCount) >= 0, "_readingCount is negative");
-            if (Volatile.Read(ref _readingCount) > 0)
-            {
-                // if _reading is true, we need to wait for it to complete
-                // if _reading is false, then future read attempts will
-                // already see the null _sessionHandle and abort.
-
-                // We block after nulling _sessionHandle but before disposing it
-                // to give a chance for a read that has already grabbed the
-                // handle to complete.
-                SpinWait.SpinUntil(() => Volatile.Read(ref _readingCount) == 0);
-            }
+            DisposeCounters();
 
             if (null != sessionHandle || null != packetHandle)
             {
@@ -1047,25 +401,6 @@ internal void Dispose()
             }
         }
 
-        internal Int32 IncrementAndObtainOpenResultCount(SqlInternalTransaction transaction)
-        {
-            _hasOpenResult = true;
-
-            if (transaction == null)
-            {
-                // If we are not passed a transaction, we are not executing under a transaction
-                // and thus we should increment the global connection result count.
-                return _parser.IncrementNonTransactedOpenResultCount();
-            }
-            else
-            {
-                // If we are passed a transaction, we are executing under a transaction
-                // and thus we should increment the transaction's result count.
-                _executedUnderTransaction = transaction;
-                return transaction.IncrementAndObtainOpenResultCount();
-            }
-        }
-
         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
         internal int IncrementPendingCallbacks()
         {
@@ -1076,308 +411,11 @@ internal int IncrementPendingCallbacks()
             return remaining;
         }
 
-        internal void SetTimeoutSeconds(int timeout)
-        {
-            SetTimeoutMilliseconds((long)timeout * 1000L);
-        }
-
-        internal void SetTimeoutMilliseconds(long timeout)
-        {
-            if (timeout <= 0)
-            {
-                // 0 or less (i.e. Timespan.Infinite) == infinite (which is represented by Int64.MaxValue)
-                _timeoutMilliseconds = 0;
-                _timeoutTime = Int64.MaxValue;
-            }
-            else
-            {
-                _timeoutMilliseconds = timeout;
-                _timeoutTime = 0;
-            }
-        }
-
         internal void StartSession(int objectID)
         {
             _allowObjectID = objectID;
         }
 
-        internal void ThrowExceptionAndWarning(bool callerHasConnectionLock = false, bool asyncClose = false)
-        {
-            _parser.ThrowExceptionAndWarning(this, callerHasConnectionLock, asyncClose);
-        }
-
-        ////////////////////////////////////////////
-        // TDS Packet/buffer manipulation methods //
-        ////////////////////////////////////////////
-
-        internal Task ExecuteFlush()
-        {
-            lock (this)
-            {
-                if (_cancelled && 1 == _outputPacketNumber)
-                {
-                    ResetBuffer();
-                    _cancelled = false;
-                    throw SQL.OperationCancelled();
-                }
-                else
-                {
-                    Task writePacketTask = WritePacket(TdsEnums.HARDFLUSH);
-                    if (writePacketTask == null)
-                    {
-                        _pendingData = true;
-                        _messageStatus = 0;
-                        return null;
-                    }
-                    else
-                    {
-                        return AsyncHelper.CreateContinuationTask(writePacketTask, () => { _pendingData = true; _messageStatus = 0; });
-                    }
-                }
-            }
-        }
-
-        // Processes the tds header that is present in the buffer
-        internal bool TryProcessHeader()
-        {
-
-            Debug.Assert(_inBytesPacket == 0, "there should not be any bytes left in packet when ReadHeader is called");
-
-            // if the header splits buffer reads - special case!
-            if ((_partialHeaderBytesRead > 0) || (_inBytesUsed + _inputHeaderLen > _inBytesRead))
-            {
-                // VSTS 219884: when some kind of MITM (man-in-the-middle) tool splits the network packets, the message header can be split over 
-                // several network packets.
-                // Note: cannot use ReadByteArray here since it uses _inBytesPacket which is not set yet.
-                do
-                {
-                    int copy = Math.Min(_inBytesRead - _inBytesUsed, _inputHeaderLen - _partialHeaderBytesRead);
-                    Debug.Assert(copy > 0, "ReadNetworkPacket read empty buffer");
-
-                    Buffer.BlockCopy(_inBuff, _inBytesUsed, _partialHeaderBuffer, _partialHeaderBytesRead, copy);
-                    _partialHeaderBytesRead += copy;
-                    _inBytesUsed += copy;
-
-                    Debug.Assert(_partialHeaderBytesRead <= _inputHeaderLen, "Read more bytes for header than required");
-                    if (_partialHeaderBytesRead == _inputHeaderLen)
-                    {
-                        // All read
-                        _partialHeaderBytesRead = 0;
-                        _inBytesPacket = ((int)_partialHeaderBuffer[TdsEnums.HEADER_LEN_FIELD_OFFSET] << 8 |
-                                  (int)_partialHeaderBuffer[TdsEnums.HEADER_LEN_FIELD_OFFSET + 1]) - _inputHeaderLen;
-
-                        _messageStatus = _partialHeaderBuffer[1];
-                        _spid = _partialHeaderBuffer[TdsEnums.SPID_OFFSET] << 8 |
-                                  _partialHeaderBuffer[TdsEnums.SPID_OFFSET + 1];
-                    }
-                    else
-                    {
-                        Debug.Assert(_inBytesUsed == _inBytesRead, "Did not use all data while reading partial header");
-
-                        // Require more data
-                        if (_parser.State == TdsParserState.Broken || _parser.State == TdsParserState.Closed)
-                        {
-                            // NOTE: ReadNetworkPacket does nothing if the parser state is closed or broken
-                            // to avoid infinite loop, we raise an exception
-                            ThrowExceptionAndWarning();
-                            // TODO: ThrowExceptionAndWarning will not raise exception if user asked to report errors as warnings
-                            return true;
-                        }
-
-                        if (!TryReadNetworkPacket())
-                        {
-                            return false;
-                        }
-
-                        if (IsTimeoutStateExpired)
-                        {
-                            ThrowExceptionAndWarning();
-                            // TODO: see the comment above
-                            return true;
-                        }
-                    }
-                } while (_partialHeaderBytesRead != 0); // This is reset to 0 once we have read everything that we need
-
-                AssertValidState();
-            }
-            else
-            {
-                // normal header processing...
-                _messageStatus = _inBuff[_inBytesUsed + 1];
-                _inBytesPacket = (_inBuff[_inBytesUsed + TdsEnums.HEADER_LEN_FIELD_OFFSET] << 8 |
-                                              _inBuff[_inBytesUsed + TdsEnums.HEADER_LEN_FIELD_OFFSET + 1]) - _inputHeaderLen;
-                _spid = _inBuff[_inBytesUsed + TdsEnums.SPID_OFFSET] << 8 |
-                                              _inBuff[_inBytesUsed + TdsEnums.SPID_OFFSET + 1];
-                _inBytesUsed += _inputHeaderLen;
-
-                AssertValidState();
-            }
-
-            if (_inBytesPacket < 0)
-            {
-                // either TDS stream is corrupted or there is multithreaded misuse of connection
-                // NOTE: usually we do not proactively apply checks to TDS data, but this situation happened several times
-                // and caused infinite loop in CleanWire (VSTFDEVDIV\DEVDIV2:149937)
-                throw SQL.ParsingError(ParsingErrorState.CorruptedTdsStream);
-            }
-
-            return true;
-        }
-
-        // This ensure that there is data available to be read in the buffer and that the header has been processed
-        // NOTE: This method (and all it calls) should be retryable without replaying a snapshot
-        internal bool TryPrepareBuffer()
-        {
-            TdsParser.ReliabilitySection.Assert("unreliable call to ReadBuffer");  // you need to setup for a thread abort somewhere before you call this method
-            Debug.Assert(_inBuff != null, "packet buffer should not be null!");
-
-            // Header spans packets, or we haven't read the header yet - process header
-            if ((_inBytesPacket == 0) && (_inBytesUsed < _inBytesRead))
-            {
-                if (!TryProcessHeader())
-                {
-                    return false;
-                }
-                Debug.Assert(_inBytesPacket != 0, "_inBytesPacket cannot be 0 after processing header!");
-                AssertValidState();
-            }
-
-            // If we're out of data, need to read more
-            if (_inBytesUsed == _inBytesRead)
-            {
-                // If the _inBytesPacket is not zero, then we have data left in the packet, but the data in the packet
-                // spans the buffer, so we can read any amount of data possible, and we do not need to call ProcessHeader
-                // because there isn't a header at the beginning of the data that we are reading.
-                if (_inBytesPacket > 0)
-                {
-                    if (!TryReadNetworkPacket())
-                    {
-                        return false;
-                    }
-
-                }
-                else if (_inBytesPacket == 0)
-                {
-                    // Else we have finished the packet and so we must read as much data as possible
-                    if (!TryReadNetworkPacket())
-                    {
-                        return false;
-                    }
-
-                    if (!TryProcessHeader())
-                    {
-                        return false;
-                    }
-
-                    Debug.Assert(_inBytesPacket != 0, "_inBytesPacket cannot be 0 after processing header!");
-                    if (_inBytesUsed == _inBytesRead)
-                    {
-                        // we read a header but didn't get anything else except it
-                        // VSTS 219884: it can happen that the TDS packet header and its data are split across two network packets.
-                        // Read at least one more byte to get/cache the first data portion of this TDS packet
-                        if (!TryReadNetworkPacket())
-                        {
-                            return false;
-                        }
-                    }
-
-                }
-                else
-                {
-                    Debug.Fail("entered negative _inBytesPacket loop");
-                }
-                AssertValidState();
-            }
-
-            return true;
-        }
-
-        internal void ResetBuffer()
-        {
-            _outBytesUsed = _outputHeaderLen;
-        }
-
-        internal void ResetPacketCounters()
-        {
-            _outputPacketNumber = 1;
-            _outputPacketCount = 0;
-        }
-
-        internal bool SetPacketSize(int size)
-        {
-            if (size > TdsEnums.MAX_PACKET_SIZE)
-            {
-                throw SQL.InvalidPacketSize();
-            }
-            Debug.Assert(size >= 1, "Cannot set packet size to less than 1.");
-            Debug.Assert((_outBuff == null && _inBuff == null) ||
-                          (_outBuff.Length == _inBuff.Length),
-                          "Buffers are not in consistent state");
-            Debug.Assert((_outBuff == null && _inBuff == null) ||
-                          this == _parser._physicalStateObj,
-                          "SetPacketSize should only be called on a stateObj with null buffers on the physicalStateObj!");
-            Debug.Assert(_inBuff == null
-                          ||
-                          (_parser.Is2005OrNewer &&
-                           _outBytesUsed == (_outputHeaderLen + BitConverter.ToInt32(_outBuff, _outputHeaderLen)) &&
-                           _outputPacketNumber == 1)
-                          ||
-                          (_outBytesUsed == _outputHeaderLen && _outputPacketNumber == 1),
-                          "SetPacketSize called with data in the buffer!");
-
-            if (_inBuff == null || _inBuff.Length != size)
-            { // We only check _inBuff, since two buffers should be consistent.
-                // Allocate or re-allocate _inBuff.
-                if (_inBuff == null)
-                {
-                    _inBuff = new byte[size];
-                    _inBytesRead = 0;
-                    _inBytesUsed = 0;
-                }
-                else if (size != _inBuff.Length)
-                {
-                    // If new size is other than existing...
-                    if (_inBytesRead > _inBytesUsed)
-                    {
-                        // if we still have data left in the buffer we must keep that array reference and then copy into new one
-                        byte[] temp = _inBuff;
-
-                        _inBuff = new byte[size];
-
-                        // copy remainder of unused data
-                        int remainingData = _inBytesRead - _inBytesUsed;
-                        if ((temp.Length < _inBytesUsed + remainingData) || (_inBuff.Length < remainingData))
-                        {
-                            string errormessage = StringsHelper.GetString(Strings.SQL_InvalidInternalPacketSize) + ' ' + temp.Length + ", " + _inBytesUsed + ", " + remainingData + ", " + _inBuff.Length;
-                            throw SQL.InvalidInternalPacketSize(errormessage);
-                        }
-                        Buffer.BlockCopy(temp, _inBytesUsed, _inBuff, 0, remainingData);
-
-                        _inBytesRead = _inBytesRead - _inBytesUsed;
-                        _inBytesUsed = 0;
-
-                        AssertValidState();
-                    }
-                    else
-                    {
-                        // buffer is empty - just create the new one that is double the size of the old one
-                        _inBuff = new byte[size];
-                        _inBytesRead = 0;
-                        _inBytesUsed = 0;
-                    }
-                }
-
-                // Always re-allocate _outBuff - assert is above to verify state.
-                _outBuff = new byte[size];
-                _outBytesUsed = _outputHeaderLen;
-
-                AssertValidState();
-                return true;
-            }
-
-            return false;
-        }
-
         ///////////////////////////////////////
         // Buffer read methods - data values //
         ///////////////////////////////////////
@@ -1419,7 +457,7 @@ public bool TryReadByteArray(Span<byte> buff, int len, out int totalRead)
                 _networkPacketTaskSource = new TaskCompletionSource<object>();
                 Thread.MemoryBarrier();
 
-                if (_forcePendingReadsToWaitForUser)
+                if (s_forcePendingReadsToWaitForUser)
                 {
                     _realNetworkPacketTaskSource = new TaskCompletionSource<object>();
                     _realNetworkPacketTaskSource.SetResult(null);
@@ -1479,7 +517,7 @@ internal bool TryReadByte(out byte value)
                 _networkPacketTaskSource = new TaskCompletionSource<object>();
                 Thread.MemoryBarrier();
 
-                if (_forcePendingReadsToWaitForUser)
+                if (s_forcePendingReadsToWaitForUser)
                 {
                     _realNetworkPacketTaskSource = new TaskCompletionSource<object>();
                     _realNetworkPacketTaskSource.SetResult(null);
@@ -1562,7 +600,7 @@ internal bool TryReadInt16(out short value)
 
                 if (!TryReadByteArray(_bTmp, 2))
                 {
-                    value = default(short);
+                    value = default;
                     return false;
                 }
 
@@ -1582,7 +620,7 @@ internal bool TryReadInt16(out short value)
             }
 
             AssertValidState();
-            value = (Int16)((buffer[offset + 1] << 8) + buffer[offset]);
+            value = (short)((buffer[offset + 1] << 8) + buffer[offset]);
             return true;
         }
 
@@ -1638,7 +676,7 @@ internal bool TryReadInt64(out long value)
                 // If the long isn't fully in the buffer, or if it isn't fully in the packet,
                 // then use ReadByteArray since the logic is there to take care of that.
 
-                int bytesRead = 0;
+                int bytesRead;
                 if (!TryReadByteArray(_bTmp.AsSpan(start: _bTmpRead), 8 - _bTmpRead, out bytesRead))
                 {
                     Debug.Assert(_bTmpRead + bytesRead <= 8, "Read more data than required");
@@ -1683,7 +721,7 @@ internal bool TryReadUInt16(out ushort value)
 
                 if (!TryReadByteArray(_bTmp, 2))
                 {
-                    value = default(ushort);
+                    value = default;
                     return false;
                 }
 
@@ -1703,7 +741,7 @@ internal bool TryReadUInt16(out ushort value)
             }
 
             AssertValidState();
-            value = (UInt16)((buffer[offset + 1] << 8) + buffer[offset]);
+            value = (ushort)((buffer[offset + 1] << 8) + buffer[offset]);
             return true;
         }
 
@@ -1725,7 +763,7 @@ internal bool TryReadUInt32(out uint value)
                 // If the int isn't fully in the buffer, or if it isn't fully in the packet,
                 // then use ReadByteArray since the logic is there to take care of that.
 
-                int bytesRead = 0;
+                int bytesRead;
                 if (!TryReadByteArray(_bTmp.AsSpan(start: _bTmpRead), 4 - _bTmpRead, out bytesRead))
                 {
                     Debug.Assert(_bTmpRead + bytesRead <= 4, "Read more data than required");
@@ -1768,7 +806,7 @@ internal bool TryReadSingle(out float value)
 
                 if (!TryReadByteArray(_bTmp, 4))
                 {
-                    value = default(float);
+                    value = default;
                     return false;
                 }
 
@@ -1802,7 +840,7 @@ internal bool TryReadDouble(out double value)
 
                 if (!TryReadByteArray(_bTmp, 8))
                 {
-                    value = default(double);
+                    value = default;
                     return false;
                 }
 
@@ -1878,8 +916,7 @@ internal bool TryReadStringWithEncoding(int length, System.Text.Encoding encodin
                 // Need to skip the current column before throwing the error - this ensures that the state shared between this and the data reader is consistent when calling DrainData
                 if (isPlp)
                 {
-                    ulong ignored;
-                    if (!_parser.TrySkipPlpValue((ulong)length, this, out ignored))
+                    if (!_parser.TrySkipPlpValue((ulong)length, this, out _))
                     {
                         value = null;
                         return false;
@@ -1901,7 +938,7 @@ internal bool TryReadStringWithEncoding(int length, System.Text.Encoding encodin
 
             if (isPlp)
             {
-                if (!TryReadPlpBytes(ref buf, 0, Int32.MaxValue, out length))
+                if (!TryReadPlpBytes(ref buf, 0, int.MaxValue, out length))
                 {
                     value = null;
                     return false;
@@ -2004,7 +1041,7 @@ internal bool TryReadPlpLength(bool returnPlpNullIfNull, out ulong lengthLeft)
                 }
                 else
                 {
-                    _longlenleft = (ulong)chunklen;
+                    _longlenleft = chunklen;
                 }
             }
 
@@ -2044,10 +1081,9 @@ internal int ReadPlpBytesChunk(byte[] buff, int offset, int len)
         // Every time you call this method increment the offst and decrease len by the value of totalBytesRead
         internal bool TryReadPlpBytes(ref byte[] buff, int offst, int len, out int totalBytesRead)
         {
-            int bytesRead = 0;
+            int bytesRead;
             int bytesLeft;
             byte[] newbuf;
-            ulong ignored;
 
             if (_longlen == 0)
             {
@@ -2071,12 +1107,12 @@ internal bool TryReadPlpBytes(ref byte[] buff, int offst, int len, out int total
             // If total length is known up front, allocate the whole buffer in one shot instead of realloc'ing and copying over each time
             if (buff == null && _longlen != TdsEnums.SQL_PLP_UNKNOWNLEN)
             {
-                buff = new byte[(int)Math.Min((int)_longlen, len)];
+                buff = new byte[(Math.Min((int)_longlen, len))];
             }
 
             if (_longlenleft == 0)
             {
-                if (!TryReadPlpLength(false, out ignored))
+                if (!TryReadPlpLength(false, out _))
                 {
                     totalBytesRead = 0;
                     return false;
@@ -2121,7 +1157,7 @@ internal bool TryReadPlpBytes(ref byte[] buff, int offst, int len, out int total
 
                 if (_longlenleft == 0)
                 { // Read the next chunk or cleanup state if hit the end
-                    if (!TryReadPlpLength(false, out ignored))
+                    if (!TryReadPlpLength(false, out _))
                     {
                         return false;
                     }
@@ -2148,16 +1184,15 @@ internal bool TryReadPlpBytes(ref byte[] buff, int offst, int len, out int total
         internal bool TrySkipLongBytes(long num)
         {
             Debug.Assert(_syncOverAsync || !_asyncReadWithoutSnapshot, "This method is not safe to call when doing sync over async");
-            int cbSkip = 0;
 
             while (num > 0)
             {
-                cbSkip = (int)Math.Min((long)Int32.MaxValue, num);
+                int cbSkip = (int)Math.Min(int.MaxValue, num);
                 if (!TryReadByteArray(Span<byte>.Empty, cbSkip))
                 {
                     return false;
                 }
-                num -= (long)cbSkip;
+                num -= cbSkip;
             }
 
             return true;
@@ -2206,7 +1241,7 @@ internal bool TryReadNetworkPacket()
                     if (_snapshot.Replay())
                     {
 #if DEBUG
-                        if (_checkNetworkPacketRetryStacks)
+                        if (s_checkNetworkPacketRetryStacks)
                         {
                             _snapshot.CheckStack(new StackTrace());
                         }
@@ -2217,7 +1252,7 @@ internal bool TryReadNetworkPacket()
 #if DEBUG
                     else
                     {
-                        if (_checkNetworkPacketRetryStacks)
+                        if (s_checkNetworkPacketRetryStacks)
                         {
                             _lastStack = new StackTrace();
                         }
@@ -2238,11 +1273,11 @@ internal bool TryReadNetworkPacket()
             ReadSni(new TaskCompletionSource<object>());
 
 #if DEBUG
-            if (_failAsyncPends)
+            if (s_failAsyncPends)
             {
                 throw new InvalidOperationException("Attempted to pend a read when _failAsyncPends test hook was enabled");
             }
-            if (_forceSyncOverAsyncAfterFirstPend)
+            if (s_forceSyncOverAsyncAfterFirstPend)
             {
                 _syncOverAsync = true;
             }
@@ -2266,7 +1301,7 @@ internal void ReadSniSyncOverAsync()
             }
 
             IntPtr readPacket = IntPtr.Zero;
-            UInt32 error;
+            uint error;
 
             RuntimeHelpers.PrepareConstrainedRegions();
             bool shouldDecrement = false;
@@ -2298,7 +1333,7 @@ internal void ReadSniSyncOverAsync()
                     Debug.Assert(ADP.s_ptrZero != readPacket, "ReadNetworkPacket cannot be null in synchronous operation!");
                     ProcessSniPacket(readPacket, 0);
 #if DEBUG
-                    if (_forcePendingReadsToWaitForUser)
+                    if (s_forcePendingReadsToWaitForUser)
                     {
                         _networkPacketTaskSource = new TaskCompletionSource<object>();
                         Thread.MemoryBarrier();
@@ -2351,7 +1386,7 @@ internal void OnConnectionClosed()
             Thread.MemoryBarrier();
 
             // then check for networkPacketTaskSource
-            var taskSource = _networkPacketTaskSource;
+            TaskCompletionSource<object> taskSource = _networkPacketTaskSource;
             if (taskSource != null)
             {
                 taskSource.TrySetException(ADP.ExceptionWithStackTrace(ADP.ClosedConnectionError()));
@@ -2427,7 +1462,7 @@ private bool OnTimeoutCore(int expectedState, int targetState, bool asyncClose =
                 {
                     if (!_attentionSent)
                     {
-                        AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, (byte)0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
+                        AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, 0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
 
                         // Grab a reference to the _networkPacketTaskSource in case it becomes null while we are trying to use it
                         TaskCompletionSource<object> source = _networkPacketTaskSource;
@@ -2540,14 +1575,14 @@ internal void ReadSni(TaskCompletionSource<object> completion)
             }
 
 #if DEBUG
-            if (_forcePendingReadsToWaitForUser)
+            if (s_forcePendingReadsToWaitForUser)
             {
                 _realNetworkPacketTaskSource = new TaskCompletionSource<object>();
             }
 #endif
 
             IntPtr readPacket = IntPtr.Zero;
-            UInt32 error = 0;
+            uint error = 0;
 
             RuntimeHelpers.PrepareConstrainedRegions();
             try
@@ -2624,7 +1659,7 @@ internal void ReadSni(TaskCompletionSource<object> completion)
                     Debug.Assert(IntPtr.Zero == readPacket, "unexpected readPacket without corresponding SNIPacketRelease");
                     ReadSniError(this, error);
 #if DEBUG
-                    if ((_forcePendingReadsToWaitForUser) && (_realNetworkPacketTaskSource != null))
+                    if ((s_forcePendingReadsToWaitForUser) && (_realNetworkPacketTaskSource != null))
                     {
                         _realNetworkPacketTaskSource.TrySetResult(null);
                     }
@@ -2689,7 +1724,7 @@ internal bool IsConnectionAlive(bool throwOnException)
                 }
                 else
                 {
-                    UInt32 error;
+                    uint error;
                     IntPtr readPacket = IntPtr.Zero;
 
                     RuntimeHelpers.PrepareConstrainedRegions();
@@ -2752,7 +1787,7 @@ internal bool ValidateSNIConnection()
                 return true;
             }
 
-            UInt32 error = TdsEnums.SNI_SUCCESS;
+            uint error = TdsEnums.SNI_SUCCESS;
             SniContext = SniContext.Snix_Connect;
             try
             {
@@ -2771,7 +1806,7 @@ internal bool ValidateSNIConnection()
         }
 
         // This method should only be called by ReadSni!  If not - it may have problems with timeouts!
-        private void ReadSniError(TdsParserStateObject stateObj, UInt32 error)
+        private void ReadSniError(TdsParserStateObject stateObj, uint error)
         {
             TdsParser.ReliabilitySection.Assert("unreliable call to ReadSniSyncError");  // you need to setup for a thread abort somewhere before you call this method
 
@@ -2788,7 +1823,7 @@ private void ReadSniError(TdsParserStateObject stateObj, UInt32 error)
                 {
                     stateObj.SetTimeoutStateStopped();
                     Debug.Assert(_parser.Connection != null, "SqlConnectionInternalTds handler can not be null at this point.");
-                    AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, (byte)0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
+                    AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, 0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
 
                     if (!stateObj._attentionSent)
                     {
@@ -2876,7 +1911,7 @@ private void ReadSniError(TdsParserStateObject stateObj, UInt32 error)
         }
 
         // TODO: - does this need to be MUSTRUN???
-        public void ProcessSniPacket(IntPtr packet, UInt32 error)
+        public void ProcessSniPacket(IntPtr packet, uint error)
         {
             if (error != 0)
             {
@@ -2892,8 +1927,8 @@ public void ProcessSniPacket(IntPtr packet, UInt32 error)
             }
             else
             {
-                UInt32 dataSize = 0;
-                UInt32 getDataError = SNINativeMethodWrapper.SNIPacketGetData(packet, _inBuff, ref dataSize);
+                uint dataSize = 0;
+                uint getDataError = SNINativeMethodWrapper.SNIPacketGetData(packet, _inBuff, ref dataSize);
 
                 if (getDataError == TdsEnums.SNI_SUCCESS)
                 {
@@ -2946,7 +1981,7 @@ private void ChangeNetworkPacketTimeout(int dueTime, int period)
             }
         }
 
-        public void ReadAsyncCallback(IntPtr key, IntPtr packet, UInt32 error)
+        public void ReadAsyncCallback(IntPtr key, IntPtr packet, uint error)
         { // Key never used.
             // Note - it's possible that when native calls managed that an asynchronous exception
             // could occur in the native->managed transition, which would
@@ -2959,7 +1994,7 @@ public void ReadAsyncCallback(IntPtr key, IntPtr packet, UInt32 error)
 
             TaskCompletionSource<object> source = _networkPacketTaskSource;
 #if DEBUG
-            if ((_forcePendingReadsToWaitForUser) && (_realNetworkPacketTaskSource != null))
+            if ((s_forcePendingReadsToWaitForUser) && (_realNetworkPacketTaskSource != null))
             {
                 source = _realNetworkPacketTaskSource;
             }
@@ -3088,7 +2123,7 @@ private void ReadAsyncCallbackCaptureException(TaskCompletionSource<object> sour
 
 #pragma warning disable 420 // a reference to a volatile field will not be treated as volatile
 
-        public void WriteAsyncCallback(IntPtr key, IntPtr packet, UInt32 sniError)
+        public void WriteAsyncCallback(IntPtr key, IntPtr packet, uint sniError)
         { // Key never used.
             RemovePacketFromPendingList(packet);
             try
@@ -3103,7 +2138,7 @@ public void WriteAsyncCallback(IntPtr key, IntPtr packet, UInt32 sniError)
                     }
                     catch (Exception e)
                     {
-                        var writeCompletionSource = _writeCompletionSource;
+                        TaskCompletionSource<object> writeCompletionSource = _writeCompletionSource;
                         if (writeCompletionSource != null)
                         {
                             writeCompletionSource.TrySetException(e);
@@ -3119,7 +2154,7 @@ public void WriteAsyncCallback(IntPtr key, IntPtr packet, UInt32 sniError)
                             writeCompletionSource = _writeCompletionSource;
                             if (writeCompletionSource != null)
                             {
-                                var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
+                                Exception delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
                                 if (delayedException != null)
                                 {
                                     writeCompletionSource.TrySetException(delayedException);
@@ -3143,7 +2178,7 @@ public void WriteAsyncCallback(IntPtr key, IntPtr packet, UInt32 sniError)
                     new Timer(obj =>
                     {
                         Interlocked.Decrement(ref _asyncWriteCount);
-                        var writeCompletionSource = _writeCompletionSource;
+                        TaskCompletionSource<object> writeCompletionSource = _writeCompletionSource;
                         if (_asyncWriteCount == 0 && writeCompletionSource != null)
                         {
                             writeCompletionSource.TrySetResult(null);
@@ -3164,7 +2199,7 @@ public void WriteAsyncCallback(IntPtr key, IntPtr packet, UInt32 sniError)
                 return;
             }
 #endif
-            var completionSource = _writeCompletionSource;
+            TaskCompletionSource<object> completionSource = _writeCompletionSource;
             if (_asyncWriteCount == 0 && completionSource != null)
             {
                 completionSource.TrySetResult(null);
@@ -3220,7 +2255,7 @@ internal Task WaitForAccumulatedWrites()
         {
             // Checked for stored exceptions
 #pragma warning disable 420 // A reference to a volatile field will not be treated as volatile - Disabling since the Interlocked APIs are volatile aware
-            var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
+            Exception delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
             if (delayedException != null)
             {
                 throw delayedException;
@@ -3282,7 +2317,7 @@ internal void WriteByte(byte b)
         //
         // Takes a byte array and writes it to the buffer.
         //
-        internal Task WriteByteArray(Byte[] b, int len, int offsetBuffer, bool canAccumulate = true, TaskCompletionSource<object> completion = null)
+        internal Task WriteByteArray(byte[] b, int len, int offsetBuffer, bool canAccumulate = true, TaskCompletionSource<object> completion = null)
         {
             try
             {
@@ -3476,10 +2511,10 @@ private void CancelWritePacket()
 
 #pragma warning disable 420 // a reference to a volatile field will not be treated as volatile
 
-        private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniError, bool canAccumulate, bool callerHasConnectionLock, bool asyncClose = false)
+        private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out uint sniError, bool canAccumulate, bool callerHasConnectionLock, bool asyncClose = false)
         {
             // Check for a stored exception
-            var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
+            Exception delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
             if (delayedException != null)
             {
                 throw delayedException;
@@ -3640,7 +2675,7 @@ internal void SendAttention(bool mustTakeWriteLock = false, bool asyncClose = fa
                     _attentionSending = true;
 
 #if DEBUG
-                    if (!_skipSendAttention)
+                    if (!s_skipSendAttention)
                     {
 #endif
                         // Take lock and send attention
@@ -3659,7 +2694,7 @@ internal void SendAttention(bool mustTakeWriteLock = false, bool asyncClose = fa
                                 return;
                             }
 
-                            UInt32 sniError;
+                            uint sniError;
                             _parser._asyncWrite = false; // stop async write 
                             SNIWritePacket(Handle, attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false, asyncClose);
                             SqlClientEventSource.Log.TryTraceEvent("<sc.TdsParser.SendAttention|{0}> Send Attention ASync.", "Info");
@@ -3698,9 +2733,8 @@ private Task WriteSni(bool canAccumulate)
             SNIPacket packet = GetResetWritePacket();
             SNINativeMethodWrapper.SNIPacketSetData(packet, _outBuff, _outBytesUsed, _securePasswords, _securePasswordOffsetsInBuffer);
 
-            uint sniError;
             Debug.Assert(Parser.Connection._parserLock.ThreadMayHaveLock(), "Thread is writing without taking the connection lock");
-            Task task = SNIWritePacket(Handle, packet, out sniError, canAccumulate, callerHasConnectionLock: true);
+            Task task = SNIWritePacket(Handle, packet, out _, canAccumulate, callerHasConnectionLock: true);
 
             // Check to see if the timeout has occurred.  This time out code is special case code to allow BCP writes to timeout to fix bug 350558, eventually we should make all writes timeout.
             if (_bulkCopyOpperationInProgress && 0 == GetTimeoutRemaining())
@@ -3709,7 +2743,7 @@ private Task WriteSni(bool canAccumulate)
                 try
                 {
                     Debug.Assert(_parser.Connection != null, "SqlConnectionInternalTds handler can not be null at this point.");
-                    AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, (byte)0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
+                    AddError(new SqlError(TdsEnums.TIMEOUT_EXPIRED, 0x00, TdsEnums.MIN_ERROR_CLASS, _parser.Server, _parser.Connection.TimeoutErrorInternal.GetErrorMessage(), "", 0, TdsEnums.SNI_WAIT_TIMEOUT));
                     _bulkCopyWriteTimeout = true;
                     SendAttention();
                     _parser.ProcessPendingAck(this);
@@ -4126,7 +3160,7 @@ internal void CheckThrowSNIException()
         internal void AssertStateIsClean()
         {
             // If our TdsParser is closed or broken, then we don't really care about our state
-            var parser = _parser;
+            TdsParser parser = _parser;
             if ((parser != null) && (parser.State != TdsParserState.Closed) && (parser.State != TdsParserState.Broken))
             {
                 // Async reads
@@ -4148,10 +3182,10 @@ internal void AssertStateIsClean()
 #if DEBUG
         internal void CompletePendingReadWithSuccess(bool resetForcePendingReadsToWait)
         {
-            var realNetworkPacketTaskSource = _realNetworkPacketTaskSource;
-            var networkPacketTaskSource = _networkPacketTaskSource;
+            TaskCompletionSource<object> realNetworkPacketTaskSource = _realNetworkPacketTaskSource;
+            TaskCompletionSource<object> networkPacketTaskSource = _networkPacketTaskSource;
 
-            Debug.Assert(_forcePendingReadsToWaitForUser, "Not forcing pends to wait for user - can't force complete");
+            Debug.Assert(s_forcePendingReadsToWaitForUser, "Not forcing pends to wait for user - can't force complete");
             Debug.Assert(networkPacketTaskSource != null, "No pending read to complete");
 
             try
@@ -4168,7 +3202,7 @@ internal void CompletePendingReadWithSuccess(bool resetForcePendingReadsToWait)
                 {
                     if (resetForcePendingReadsToWait)
                     {
-                        _forcePendingReadsToWaitForUser = false;
+                        s_forcePendingReadsToWaitForUser = false;
                     }
 
                     networkPacketTaskSource.TrySetResult(null);
@@ -4178,10 +3212,10 @@ internal void CompletePendingReadWithSuccess(bool resetForcePendingReadsToWait)
 
         internal void CompletePendingReadWithFailure(int errorCode, bool resetForcePendingReadsToWait)
         {
-            var realNetworkPacketTaskSource = _realNetworkPacketTaskSource;
-            var networkPacketTaskSource = _networkPacketTaskSource;
+            TaskCompletionSource<object> realNetworkPacketTaskSource = _realNetworkPacketTaskSource;
+            TaskCompletionSource<object> networkPacketTaskSource = _networkPacketTaskSource;
 
-            Debug.Assert(_forcePendingReadsToWaitForUser, "Not forcing pends to wait for user - can't force complete");
+            Debug.Assert(s_forcePendingReadsToWaitForUser, "Not forcing pends to wait for user - can't force complete");
             Debug.Assert(networkPacketTaskSource != null, "No pending read to complete");
 
             try
@@ -4198,7 +3232,7 @@ internal void CompletePendingReadWithFailure(int errorCode, bool resetForcePendi
                 {
                     if (resetForcePendingReadsToWait)
                     {
-                        _forcePendingReadsToWaitForUser = false;
+                        s_forcePendingReadsToWaitForUser = false;
                     }
 
                     AddError(new SqlError(errorCode, 0x00, TdsEnums.FATAL_ERROR_CLASS, _parser.Server, string.Empty, string.Empty, 0));
@@ -4265,7 +3299,7 @@ public StateSnapshot(TdsParserStateObject state)
 
             internal bool DoPend()
             {
-                if (_failAsyncPends || !_forceAllPends)
+                if (s_failAsyncPends || !s_forceAllPends)
                 {
                     return false;
                 }
@@ -4424,43 +3458,5 @@ internal void PrepareReplay()
                 ResetSnapshotState();
             }
         }
-
-        /*
-
-        // leave this in. comes handy if you have to do Console.WriteLine style debugging ;)
-                private void DumpBuffer() {
-                    Console.WriteLine("dumping buffer");
-                    Console.WriteLine("_inBytesRead = {0}", _inBytesRead);
-                    Console.WriteLine("_inBytesUsed = {0}", _inBytesUsed);
-                    int cc = 0; // character counter
-                    int i;
-                    Console.WriteLine("used buffer:");
-                    for (i=0; i< _inBytesUsed; i++) {
-                        if (cc==16) {
-                            Console.WriteLine();
-                            cc = 0;
-                        }
-                        Console.Write("{0,-2:X2} ", _inBuff[i]);
-                        cc++;
-                    }
-                    if (cc>0) {
-                        Console.WriteLine();
-                    }
-
-                    cc = 0;
-                    Console.WriteLine("unused buffer:");
-                    for (i=_inBytesUsed; i<_inBytesRead; i++) {
-                        if (cc==16) {
-                            Console.WriteLine();
-                            cc = 0;
-                        }
-                        Console.Write("{0,-2:X2} ", _inBuff[i]);
-                        cc++;
-                    }
-                    if (cc>0) {
-                        Console.WriteLine();
-                    }
-                }
-        */
     }
 }
diff --git a/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs b/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
new file mode 100644
index 0000000000..86f51fba2a
--- /dev/null
+++ b/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
@@ -0,0 +1,1060 @@
+// 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;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Security;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Data.Common;
+
+namespace Microsoft.Data.SqlClient
+{
+    sealed internal class LastIOTimer
+    {
+        internal long _value;
+    }
+
+    partial class TdsParserStateObject
+    {
+        private static int s_objectTypeCount; // EventSource counter
+        internal readonly int _objectID = Interlocked.Increment(ref s_objectTypeCount);
+
+        [Flags]
+        internal enum SnapshottedStateFlags : byte
+        {
+            None = 0,
+            PendingData = 1 << 1,
+            OpenResult = 1 << 2,
+            ErrorTokenReceived = 1 << 3,  // Keep track of whether an error was received for the result. This is reset upon each done token
+            ColMetaDataReceived = 1 << 4, // Used to keep track of when to fire StatementCompleted event.
+            AttentionReceived = 1 << 5    // NOTE: Received is not volatile as it is only ever accessed\modified by TryRun its callees (i.e. single threaded access)
+        }
+
+        private sealed class TimeoutState
+        {
+            public const int Stopped = 0;
+            public const int Running = 1;
+            public const int ExpiredAsync = 2;
+            public const int ExpiredSync = 3;
+
+            private readonly int _value;
+
+            public TimeoutState(int value)
+            {
+                _value = value;
+            }
+
+            public int IdentityValue => _value;
+        }
+
+        private const int AttentionTimeoutSeconds = 5;
+
+        // Ticks to consider a connection "good" after a successful I/O (10,000 ticks = 1 ms)
+        // The resolution of the timer is typically in the range 10 to 16 milliseconds according to msdn.
+        // We choose a value that is smaller than the likely timer resolution, but
+        // large enough to ensure that check connection execution will be 0.1% or less
+        // of very small open, query, close loops.
+        private const long CheckConnectionWindow = 50000;
+
+        protected readonly TdsParser _parser;                            // TdsParser pointer
+        private readonly WeakReference<object> _owner = new(null);   // the owner of this session, used to track when it's been orphaned
+        internal SqlDataReader.SharedState _readerState;                    // susbset of SqlDataReader state (if it is the owner) necessary for parsing abandoned results in TDS
+        private int _activateCount;                     // 0 when we're in the pool, 1 when we're not, all others are an error
+
+        // Two buffers exist in tdsparser, an in buffer and an out buffer.  For the out buffer, only
+        // one bookkeeping variable is needed, the number of bytes used in the buffer.  For the in buffer,
+        // three variables are actually needed.  First, we need to record from the netlib how many bytes it
+        // read from the netlib, this variable is _inBytesRead.  Then, we need to also keep track of how many
+        // bytes we have used as we consume the bytes from the buffer, that variable is _inBytesUsed.  Third,
+        // we need to keep track of how many bytes are left in the packet, so that we know when we have reached
+        // the end of the packet and so we need to consume the next header.  That variable is _inBytesPacket.
+
+        // Header length constants
+        internal readonly int _inputHeaderLen = TdsEnums.HEADER_LEN;
+        internal readonly int _outputHeaderLen = TdsEnums.HEADER_LEN;
+
+        // Out buffer variables
+        internal byte[] _outBuff;                         // internal write buffer - initialize on login
+        internal int _outBytesUsed = TdsEnums.HEADER_LEN; // number of bytes used in internal write buffer - initialize past header
+        
+        // In buffer variables
+
+        /// <summary>
+        /// internal read buffer - initialize on login
+        /// </summary>
+        protected byte[] _inBuff;
+        /// <summary>
+        /// number of bytes used in internal read buffer
+        /// </summary>
+        internal int _inBytesUsed;
+        /// <summary>
+        /// number of bytes read into internal read buffer
+        /// </summary>
+        internal int _inBytesRead;
+
+        /// <summary>
+        /// number of bytes left in packet
+        /// </summary>
+        internal int _inBytesPacket;
+
+        internal int _spid;                                 // SPID of the current connection
+
+        // Packet state variables
+        internal byte _outputMessageType;                   // tds header type
+        internal byte _messageStatus;                       // tds header status
+        internal byte _outputPacketNumber = 1;              // number of packets sent to server in message - start at 1 per ramas
+        internal uint _outputPacketCount;
+
+        internal volatile bool _fResetEventOwned;           // ResetEvent serializing call to sp_reset_connection
+        internal volatile bool _fResetConnectionSent;       // For multiple packet execute
+        internal bool _bulkCopyOpperationInProgress;        // Set to true during bulk copy and used to turn toggle write timeouts.
+        internal bool _bulkCopyWriteTimeout;                // Set to trun when _bulkCopyOperationInProgress is trun and write timeout happens
+
+        // SNI variables
+        /// <summary>
+        /// Used to synchronize access to _writePacketCache and _pendingWritePackets
+        /// </summary>
+        protected readonly object _writePacketLockObject = new object();
+
+        // Async variables
+        private int _pendingCallbacks;                      // we increment this before each async read/write call and decrement it in the callback.  We use this to determine when to release the GcHandle...
+
+        // Timeout variables
+        private long _timeoutMilliseconds;
+        private long _timeoutTime;                          // variable used for timeout computations, holds the value of the hi-res performance counter at which this request should expire
+        private int _timeoutState;                          // expected to be one of the constant values TimeoutStopped, TimeoutRunning, TimeoutExpiredAsync, TimeoutExpiredSync
+        private int _timeoutIdentitySource;
+        private volatile int _timeoutIdentityValue;
+        internal volatile bool _attentionSent;              // true if we sent an Attention to the server
+        internal volatile bool _attentionSending;
+        private readonly TimerCallback _onTimeoutAsync;
+
+        // Below 2 properties are used to enforce timeout delays in code to 
+        // reproduce issues related to theadpool starvation and timeout delay.
+        // It should always be set to false by default, and only be enabled during testing.
+        internal bool _enforceTimeoutDelay = false;
+        internal int _enforcedTimeoutDelayInMilliSeconds = 5000;
+
+        private readonly LastIOTimer _lastSuccessfulIOTimer;
+
+        // secure password information to be stored
+        //  At maximum number of secure string that need to be stored is two; one for login password and the other for new change password
+        private readonly SecureString[] _securePasswords = new SecureString[2] { null, null };
+        private readonly int[] _securePasswordOffsetsInBuffer = new int[2];
+
+        // This variable is used to track whether another thread has requested a cancel.  The
+        // synchronization points are
+        //   On the user's execute thread:
+        //     1) the first packet write
+        //     2) session close - return this stateObj to the session pool
+        //   On cancel thread we only have the cancel call.
+        // Currently all access to this variable is inside a lock, The state diagram is:
+        // 1) pre first packet write, if cancel is requested, set variable so exception is triggered
+        //    on user thread when first packet write is attempted
+        // 2) post first packet write, but before session return - a call to cancel will send an
+        //    attention to the server
+        // 3) post session close - no attention is allowed
+        private bool _cancelled;
+        private const int WaitForCancellationLockPollTimeout = 100;
+
+        // Cache the transaction for which this command was executed so upon completion we can
+        // decrement the appropriate result count.
+        internal SqlInternalTransaction _executedUnderTransaction;
+
+        // TDS stream processing variables
+        internal ulong _longlen;                                     // plp data length indicator
+        internal ulong _longlenleft;                                 // Length of data left to read (64 bit lengths)
+        internal int[] _decimalBits;                // scratch buffer for decimal/numeric data
+        internal byte[] _bTmp = new byte[TdsEnums.SQL2005_HEADER_LEN];  // Scratch buffer for misc use
+        internal int _bTmpRead;                   // Counter for number of temporary bytes read
+        internal Decoder _plpdecoder;             // Decoder object to process plp character data
+        internal bool _accumulateInfoEvents;               // TRUE - accumulate info messages during TdsParser.Run, FALSE - fire them
+        internal List<SqlError> _pendingInfoEvents;
+        internal byte[] _bLongBytes;                 // scratch buffer to serialize Long values (8 bytes).
+        internal byte[] _bIntBytes;                 // scratch buffer to serialize Int values (4 bytes).
+        internal byte[] _bShortBytes;                 // scratch buffer to serialize Short values (2 bytes).
+        internal byte[] _bDecimalBytes;                 // scratch buffer to serialize decimal values (17 bytes).
+
+        // DO NOT USE THIS BUFFER FOR OTHER THINGS.
+        // ProcessHeader can be called ANYTIME while doing network reads.
+        private readonly byte[] _partialHeaderBuffer = new byte[TdsEnums.HEADER_LEN];   // Scratch buffer for ProcessHeader
+        internal int _partialHeaderBytesRead;
+
+        internal _SqlMetaDataSet _cleanupMetaData;
+        internal _SqlMetaDataSetCollection _cleanupAltMetaDataSetArray;
+
+        private SniContext _sniContext = SniContext.Undefined;
+#if DEBUG
+        private SniContext _debugOnlyCopyOfSniContext = SniContext.Undefined;
+#endif
+
+        private bool _bcpLock;
+
+        // Null bitmap compression (NBC) information for the current row
+        private NullBitmap _nullBitmapInfo;
+
+        // Async
+        internal TaskCompletionSource<object> _networkPacketTaskSource;
+        private Timer _networkPacketTimeout;
+        internal bool _syncOverAsync = true;
+        private bool _snapshotReplay;
+        private StateSnapshot _snapshot;
+        internal ExecutionContext _executionContext;
+        internal bool _asyncReadWithoutSnapshot;
+#if DEBUG
+        // Used to override the assert than ensures that the stacktraces on subsequent replays are the same
+        // This is useful is you are purposefully running the replay from a different thread (e.g. during SqlDataReader.Close)
+        internal bool _permitReplayStackTraceToDiffer;
+
+        // Used to indicate that the higher level object believes that this stateObj has enough data to complete an operation
+        // If this stateObj has to read, then it will raise an assert
+        internal bool _shouldHaveEnoughData;
+#endif
+
+        // local exceptions to cache warnings and errors
+        internal SqlErrorCollection _errors;
+        internal SqlErrorCollection _warnings;
+        internal object _errorAndWarningsLock = new object();
+        private bool _hasErrorOrWarning;
+
+        // local exceptions to cache warnings and errors that occurred prior to sending attention
+        internal SqlErrorCollection _preAttentionErrors;
+        internal SqlErrorCollection _preAttentionWarnings;
+
+        private volatile TaskCompletionSource<object> _writeCompletionSource;
+        protected volatile int _asyncWriteCount;
+        private volatile Exception _delayedWriteAsyncCallbackException; // set by write async callback if completion source is not yet created
+
+        // _readingcount is incremented when we are about to read.
+        // We check the parser state afterwards.
+        // When the read is completed, we decrement it before handling errors
+        // as the error handling may end up calling Dispose.
+        private int _readingCount;
+
+        // Test hooks
+#if DEBUG
+        // This is a test hook to enable testing of the retry paths.
+        // When set to true, almost every possible retry point will be attempted.
+        // This will drastically impact performance.
+        //
+        // Sample code to enable:
+        //
+        //    Type type = typeof(SqlDataReader).Assembly.GetType("Microsoft.Data.SqlClient.TdsParserStateObject");
+        //    System.Reflection.FieldInfo field = type.GetField("_forceAllPends", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static);
+        //    if (field != null) {
+        //        field.SetValue(null, true);
+        //    }
+        //
+        internal static bool s_forceAllPends = false;
+
+        // set this while making a call that should not block.
+        // instead of blocking it will fail.
+        internal static bool s_failAsyncPends = false;
+
+        // If this is set and an async read is made, then
+        // we will switch to syncOverAsync mode for the
+        // remainder of the async operation.
+        internal static bool s_forceSyncOverAsyncAfterFirstPend = false;
+
+        // Requests to send attention will be ignored when _skipSendAttention is true.
+        // This is useful to simulate circumstances where timeouts do not recover.
+        internal static bool s_skipSendAttention = false;
+
+        // Prevents any pending read from completing until the user signals it using
+        // CompletePendingReadWithSuccess() or CompletePendingReadWithFailure(int errorCode) in SqlCommand\SqlDataReader
+        internal static bool s_forcePendingReadsToWaitForUser = false;
+        internal TaskCompletionSource<object> _realNetworkPacketTaskSource;
+
+        // Field is never assigned to, and will always have its default value
+#pragma warning disable 0649
+        // Set to true to enable checking the call stacks match when packet retry occurs.
+        internal static bool s_checkNetworkPacketRetryStacks = false;
+#pragma warning restore 0649
+#endif
+
+        //////////////////
+        // Constructors //
+        //////////////////
+
+        internal TdsParserStateObject(TdsParser parser)
+        {
+            // Construct a physical connection
+            Debug.Assert(null != parser, "no parser?");
+            _parser = parser;
+            _onTimeoutAsync = OnTimeoutAsync;
+
+            // For physical connection, initialize to default login packet size.
+            SetPacketSize(TdsEnums.DEFAULT_LOGIN_PACKET_SIZE);
+
+            // we post a callback that represents the call to dispose; once the
+            // object is disposed, the next callback will cause the GC Handle to
+            // be released.
+            IncrementPendingCallbacks();
+            _lastSuccessfulIOTimer = new LastIOTimer();
+        }
+
+        ////////////////
+        // Properties //
+        ////////////////
+
+        internal int ObjectID => _objectID;
+
+        // BcpLock - use to lock this object if there is a potential risk of using this object
+        // between tds packets
+        internal bool BcpLock
+        {
+            get => _bcpLock;
+            set => _bcpLock = value;
+        }
+
+#if DEBUG
+        internal SniContext DebugOnlyCopyOfSniContext => _debugOnlyCopyOfSniContext;
+
+        internal void InvalidateDebugOnlyCopyOfSniContext()
+        {
+            _debugOnlyCopyOfSniContext = SniContext.Undefined;
+        }
+#endif
+
+        internal bool IsOrphaned
+        {
+            get
+            {
+                bool isAlive = _owner.TryGetTarget(out object target);
+                Debug.Assert((0 == _activateCount && !isAlive) // in pool
+                             || (1 == _activateCount && isAlive && target != null)
+                             || (1 == _activateCount && !isAlive), "Unknown state on TdsParserStateObject.IsOrphaned!");
+                return (0 != _activateCount && !isAlive);
+            }
+        }
+
+        internal object Owner
+        {
+            set
+            {
+                Debug.Assert(value == null || !_owner.TryGetTarget(out object target) || value is SqlDataReader reader1 && reader1.Command == target, "Should not be changing the owner of an owned stateObj");
+                if (value is SqlDataReader reader)
+                {
+                    _readerState = reader._sharedState;
+                }
+                else
+                {
+                    _readerState = null;
+                }
+                _owner.SetTarget(value);
+            }
+        }
+
+        internal bool HasOwner => _owner.TryGetTarget(out object _);
+
+        internal TdsParser Parser => _parser;
+
+        internal SniContext SniContext
+        {
+            get
+            {
+                return _sniContext;
+            }
+            set
+            {
+                _sniContext = value;
+#if DEBUG
+                _debugOnlyCopyOfSniContext = value;
+#endif
+            }
+        }
+
+        internal bool TimeoutHasExpired
+        {
+            get
+            {
+                Debug.Assert(0 == _timeoutMilliseconds || 0 == _timeoutTime, "_timeoutTime hasn't been reset");
+                return TdsParserStaticMethods.TimeoutHasExpired(_timeoutTime);
+            }
+        }
+
+        internal long TimeoutTime
+        {
+            get
+            {
+                if (0 != _timeoutMilliseconds)
+                {
+                    _timeoutTime = TdsParserStaticMethods.GetTimeout(_timeoutMilliseconds);
+                    _timeoutMilliseconds = 0;
+                }
+                return _timeoutTime;
+            }
+            set
+            {
+                _timeoutMilliseconds = 0;
+                _timeoutTime = value;
+            }
+        }
+
+        internal int GetTimeoutRemaining()
+        {
+            int remaining;
+            if (0 != _timeoutMilliseconds)
+            {
+                remaining = (int)Math.Min((long)int.MaxValue, _timeoutMilliseconds);
+                _timeoutTime = TdsParserStaticMethods.GetTimeout(_timeoutMilliseconds);
+                _timeoutMilliseconds = 0;
+            }
+            else
+            {
+                remaining = TdsParserStaticMethods.GetTimeoutMilliseconds(_timeoutTime);
+            }
+            return remaining;
+        }
+
+        internal bool TryStartNewRow(bool isNullCompressed, int nullBitmapColumnsCount = 0)
+        {
+            Debug.Assert(!isNullCompressed || nullBitmapColumnsCount > 0, "Null-Compressed row requires columns count");
+
+            _snapshot?.CloneNullBitmapInfo();
+
+            // initialize or unset null bitmap information for the current row
+            if (isNullCompressed)
+            {
+                // assert that NBCROW is not in use by 2005 or before
+                Debug.Assert(_parser.Is2008OrNewer, "NBCROW is sent by pre-2008 server");
+
+                if (!_nullBitmapInfo.TryInitialize(this, nullBitmapColumnsCount))
+                {
+                    return false;
+                }
+            }
+            else
+            {
+                _nullBitmapInfo.Clean();
+            }
+
+            return true;
+        }
+
+        internal bool IsRowTokenReady()
+        {
+            // Removing one byte since TryReadByteArray\TryReadByte will aggressively read the next packet if there is no data left - so we need to ensure there is a spare byte
+            int bytesRemaining = Math.Min(_inBytesPacket, _inBytesRead - _inBytesUsed) - 1;
+
+            if (bytesRemaining > 0)
+            {
+                if (_inBuff[_inBytesUsed] == TdsEnums.SQLROW)
+                {
+                    // At a row token, so we're ready
+                    return true;
+                }
+                else if (_inBuff[_inBytesUsed] == TdsEnums.SQLNBCROW)
+                {
+                    // NBC row token, ensure that we have enough data for the bitmap
+                    // SQLNBCROW + Null Bitmap (copied from NullBitmap.TryInitialize)
+                    int bytesToRead = 1 + (_cleanupMetaData.Length + 7) / 8;
+                    return (bytesToRead <= bytesRemaining);
+                }
+            }
+
+            // No data left, or not at a row token
+            return false;
+        }
+
+        internal bool IsNullCompressionBitSet(int columnOrdinal)
+        {
+            return _nullBitmapInfo.IsGuaranteedNull(columnOrdinal);
+        }
+
+        private partial struct NullBitmap
+        {
+            private byte[] _nullBitmap;
+            private int _columnsCount; // set to 0 if not used or > 0 for NBC rows
+
+            internal bool ReferenceEquals(NullBitmap obj)
+            {
+                return object.ReferenceEquals(_nullBitmap, obj._nullBitmap);
+            }
+
+            internal NullBitmap Clone()
+            {
+                NullBitmap newBitmap = new NullBitmap();
+                newBitmap._nullBitmap = _nullBitmap == null ? null : (byte[])_nullBitmap.Clone();
+                newBitmap._columnsCount = _columnsCount;
+                return newBitmap;
+            }
+
+            internal void Clean()
+            {
+                _columnsCount = 0;
+                // no need to free _nullBitmap array - it is cached for the next row
+            }
+
+            /// <summary>
+            /// If this method returns true, the value is guaranteed to be null. This is not true vice versa:
+            /// if the bitmap value is false (if this method returns false), the value can be either null or non-null - no guarantee in this case.
+            /// To determine whether it is null or not, read it from the TDS (per NBCROW design spec, for IMAGE/TEXT/NTEXT columns server might send
+            /// bitmap = 0, when the actual value is null).
+            /// </summary>
+            internal bool IsGuaranteedNull(int columnOrdinal)
+            {
+                if (_columnsCount == 0)
+                {
+                    // not an NBC row
+                    return false;
+                }
+
+                Debug.Assert(columnOrdinal >= 0 && columnOrdinal < _columnsCount, "Invalid column ordinal");
+
+                byte testBit = (byte)(1 << (columnOrdinal & 0x7)); // columnOrdinal & 0x7 == columnOrdinal MOD 0x7
+                byte testByte = _nullBitmap[columnOrdinal >> 3];
+                return (testBit & testByte) != 0;
+            }
+        }
+
+
+        /////////////////////
+        // General methods //
+        /////////////////////
+
+        // If this object is part of a TdsParserSessionPool, then this *must* be called inside the pool's lock
+        internal void Activate(object owner)
+        {
+            Debug.Assert(_parser.MARSOn, "Can not activate a non-MARS connection");
+            Owner = owner; // must assign an owner for reclamation to work
+            int result = Interlocked.Increment(ref _activateCount);   // must have non-zero activation count for reclamation to work too.
+            Debug.Assert(result == 1, "invalid deactivate count");
+        }
+
+        // CancelRequest - use to cancel while writing a request to the server
+        //
+        // o none of the request might have been sent to the server, simply reset the buffer,
+        //   sending attention does not hurt
+        // o the request was partially written. Send an ignore header to the server. attention is
+        //   required if the server was waiting for data (e.g. insert bulk rows)
+        // o the request was completely written out and the server started to process the request.
+        //   attention is required to have the server stop processing.
+        //
+        internal void CancelRequest()
+        {
+            ResetBuffer();    // clear out unsent buffer
+            // VSDD#903514, if the first sqlbulkcopy timeout, _outputPacketNumber may not be 1,
+            // the next sqlbulkcopy (same connection string) requires this to be 1, hence reset
+            // it here when exception happens in the first sqlbulkcopy
+            ResetPacketCounters();
+
+            // VSDD#907507, if bulkcopy write timeout happens, it already sent the attention,
+            // so no need to send it again
+            if (!_bulkCopyWriteTimeout)
+            {
+                SendAttention();
+                Parser.ProcessPendingAck(this);
+            }
+        }
+
+        public void CheckSetResetConnectionState(uint error, CallbackType callbackType)
+        {
+            // Should only be called for MARS - that is the only time we need to take
+            // the ResetConnection lock!
+
+            // SQL BU DT 333026 - It was raised in a security review by Microsoft questioning whether
+            // we need to actually process the resulting packet (sp_reset ack or error) to know if the
+            // reset actually succeeded.  There was a concern that if the reset failed and we proceeded
+            // there might be a security issue present.  We have been assured by the server that if
+            // sp_reset fails, they guarantee they will kill the resulting connection.  So - it is
+            // safe for us to simply receive the packet and then consume the pre-login later.
+
+            Debug.Assert(_parser.MARSOn, "Should not be calling CheckSetResetConnectionState on non MARS connection");
+
+            if (_fResetEventOwned)
+            {
+                if (callbackType == CallbackType.Read && TdsEnums.SNI_SUCCESS == error)
+                {
+                    // RESET SUCCEEDED!
+                    // If we are on read callback and no error occurred (and we own reset event) -
+                    // then we sent the sp_reset_connection and so we need to reset sp_reset_connection
+                    // flag to false, and then release the ResetEvent.
+                    _parser._fResetConnection = false;
+                    _fResetConnectionSent = false;
+                    _fResetEventOwned = !_parser._resetConnectionEvent.Set();
+                    Debug.Assert(!_fResetEventOwned, "Invalid AutoResetEvent state!");
+                }
+
+                if (TdsEnums.SNI_SUCCESS != error)
+                {
+                    // RESET FAILED!
+
+                    // If write or read failed with reset, we need to clear event but not mark connection
+                    // as reset.
+                    _fResetConnectionSent = false;
+                    _fResetEventOwned = !_parser._resetConnectionEvent.Set();
+                    Debug.Assert(!_fResetEventOwned, "Invalid AutoResetEvent state!");
+                }
+            }
+        }
+
+        internal void CloseSession()
+        {
+            ResetCancelAndProcessAttention();
+#if DEBUG
+            InvalidateDebugOnlyCopyOfSniContext();
+#endif
+            Parser.PutSession(this);
+        }
+
+        internal bool Deactivate()
+        {
+            bool goodForReuse = false;
+
+            try
+            {
+                TdsParserState state = Parser.State;
+                if (state != TdsParserState.Broken && state != TdsParserState.Closed)
+                {
+                    if (HasPendingData)
+                    {
+                        Parser.DrainData(this); // This may throw - taking us to catch block.c
+                    }
+
+                    if (HasOpenResult)
+                    { // SQL BU DT 383773 - need to decrement openResultCount for all pending operations.
+                        DecrementOpenResultCount();
+                    }
+
+                    ResetCancelAndProcessAttention();
+                    goodForReuse = true;
+                }
+            }
+            catch (Exception e)
+            {
+                if (!ADP.IsCatchableExceptionType(e))
+                {
+                    throw;
+                }
+
+                ADP.TraceExceptionWithoutRethrow(e);
+            }
+            return goodForReuse;
+        }
+
+        // If this object is part of a TdsParserSessionPool, then this *must* be called inside the pool's lock
+        internal void RemoveOwner()
+        {
+            if (_parser.MARSOn)
+            {
+                // We only care about the activation count for MARS connections
+                int result = Interlocked.Decrement(ref _activateCount);   // must have non-zero activation count for reclamation to work too.
+                Debug.Assert(result == 0, "invalid deactivate count");
+            }
+            Owner = null;
+        }
+
+        internal void DecrementOpenResultCount()
+        {
+            if (_executedUnderTransaction == null)
+            {
+                // If we were not executed under a transaction - decrement the global count
+                // on the parser.
+                SqlClientEventSource.Log.TryTraceEvent("TdsParserStateObject.DecrementOpenResultCount | INFO | State Object Id {0}, Processing Attention.", _objectID);
+                _parser.DecrementNonTransactedOpenResultCount();
+            }
+            else
+            {
+                // If we were executed under a transaction - decrement the count on the transaction.
+                _executedUnderTransaction.DecrementAndObtainOpenResultCount();
+                _executedUnderTransaction = null;
+            }
+            HasOpenResult = false;
+        }
+
+        internal void DisposeCounters()
+        {
+            Timer networkPacketTimeout = _networkPacketTimeout;
+            if (networkPacketTimeout != null)
+            {
+                _networkPacketTimeout = null;
+                networkPacketTimeout.Dispose();
+            }
+
+            Debug.Assert(Volatile.Read(ref _readingCount) >= 0, "_readingCount is negative");
+            if (Volatile.Read(ref _readingCount) > 0)
+            {
+                // if _reading is true, we need to wait for it to complete
+                // if _reading is false, then future read attempts will
+                // already see the null _sessionHandle and abort.
+
+                // We block after nulling _sessionHandle but before disposing it
+                // to give a chance for a read that has already grabbed the
+                // handle to complete.
+                SpinWait.SpinUntil(() => Volatile.Read(ref _readingCount) == 0);
+            }
+        }
+
+        internal int IncrementAndObtainOpenResultCount(SqlInternalTransaction transaction)
+        {
+            HasOpenResult = true;
+
+            if (transaction == null)
+            {
+                // If we are not passed a transaction, we are not executing under a transaction
+                // and thus we should increment the global connection result count.
+                return _parser.IncrementNonTransactedOpenResultCount();
+            }
+            else
+            {
+                // If we are passed a transaction, we are executing under a transaction
+                // and thus we should increment the transaction's result count.
+                _executedUnderTransaction = transaction;
+                return transaction.IncrementAndObtainOpenResultCount();
+            }
+        }
+
+        internal void SetTimeoutSeconds(int timeout)
+        {
+            SetTimeoutMilliseconds((long)timeout * 1000L);
+        }
+
+        internal void SetTimeoutMilliseconds(long timeout)
+        {
+            if (timeout <= 0)
+            {
+                // 0 or less (i.e. Timespan.Infinite) == infinite (which is represented by Int64.MaxValue)
+                _timeoutMilliseconds = 0;
+                _timeoutTime = long.MaxValue;
+            }
+            else
+            {
+                _timeoutMilliseconds = timeout;
+                _timeoutTime = 0;
+            }
+        }
+
+        internal void ThrowExceptionAndWarning(bool callerHasConnectionLock = false, bool asyncClose = false)
+        {
+            _parser.ThrowExceptionAndWarning(this, callerHasConnectionLock, asyncClose);
+        }
+
+        ////////////////////////////////////////////
+        // TDS Packet/buffer manipulation methods //
+        ////////////////////////////////////////////
+
+        internal Task ExecuteFlush()
+        {
+            lock (this)
+            {
+                if (_cancelled && 1 == _outputPacketNumber)
+                {
+                    ResetBuffer();
+                    _cancelled = false;
+                    throw SQL.OperationCancelled();
+                }
+                else
+                {
+                    Task writePacketTask = WritePacket(TdsEnums.HARDFLUSH);
+                    if (writePacketTask == null)
+                    {
+                        HasPendingData = true;
+                        _messageStatus = 0;
+                        return null;
+                    }
+                    else
+                    {
+                        return AsyncHelper.CreateContinuationTaskWithState(
+                            task: writePacketTask,
+                            state: this,
+                            onSuccess: static (object state) =>
+                            {
+                                TdsParserStateObject stateObject = (TdsParserStateObject)state;
+                                stateObject.HasPendingData = true;
+                                stateObject._messageStatus = 0;
+                            }
+                        );
+                    }
+                }
+            }
+        }
+
+        // Processes the tds header that is present in the buffer
+        internal bool TryProcessHeader()
+        {
+            Debug.Assert(_inBytesPacket == 0, "there should not be any bytes left in packet when ReadHeader is called");
+
+            // if the header splits buffer reads - special case!
+            if ((_partialHeaderBytesRead > 0) || (_inBytesUsed + _inputHeaderLen > _inBytesRead))
+            {
+                // VSTS 219884: when some kind of MITM (man-in-the-middle) tool splits the network packets, the message header can be split over
+                // several network packets.
+                // Note: cannot use ReadByteArray here since it uses _inBytesPacket which is not set yet.
+                do
+                {
+                    int copy = Math.Min(_inBytesRead - _inBytesUsed, _inputHeaderLen - _partialHeaderBytesRead);
+                    Debug.Assert(copy > 0, "ReadNetworkPacket read empty buffer");
+
+                    Buffer.BlockCopy(_inBuff, _inBytesUsed, _partialHeaderBuffer, _partialHeaderBytesRead, copy);
+                    _partialHeaderBytesRead += copy;
+                    _inBytesUsed += copy;
+
+                    Debug.Assert(_partialHeaderBytesRead <= _inputHeaderLen, "Read more bytes for header than required");
+                    if (_partialHeaderBytesRead == _inputHeaderLen)
+                    {
+                        // All read
+                        _partialHeaderBytesRead = 0;
+                        _inBytesPacket = ((int)_partialHeaderBuffer[TdsEnums.HEADER_LEN_FIELD_OFFSET] << 8 |
+                                  (int)_partialHeaderBuffer[TdsEnums.HEADER_LEN_FIELD_OFFSET + 1]) - _inputHeaderLen;
+
+                        _messageStatus = _partialHeaderBuffer[1];
+                        _spid = _partialHeaderBuffer[TdsEnums.SPID_OFFSET] << 8 |
+                                  _partialHeaderBuffer[TdsEnums.SPID_OFFSET + 1];
+
+                        SqlClientEventSource.Log.TryAdvancedTraceEvent("TdsParserStateObject.TryProcessHeader | ADV | State Object Id {0}, Client Connection Id {1}, Server process Id (SPID) {2}", _objectID, _parser?.Connection?.ClientConnectionId, _spid);
+                    }
+                    else
+                    {
+                        Debug.Assert(_inBytesUsed == _inBytesRead, "Did not use all data while reading partial header");
+
+                        // Require more data
+                        if (_parser.State == TdsParserState.Broken || _parser.State == TdsParserState.Closed)
+                        {
+                            // NOTE: ReadNetworkPacket does nothing if the parser state is closed or broken
+                            // to avoid infinite loop, we raise an exception
+                            ThrowExceptionAndWarning();
+                            return true;
+                        }
+
+                        if (!TryReadNetworkPacket())
+                        {
+                            return false;
+                        }
+
+                        if (IsTimeoutStateExpired)
+                        {
+                            ThrowExceptionAndWarning();
+                            return true;
+                        }
+                    }
+                } while (_partialHeaderBytesRead != 0); // This is reset to 0 once we have read everything that we need
+
+                AssertValidState();
+            }
+            else
+            {
+                // normal header processing...
+                _messageStatus = _inBuff[_inBytesUsed + 1];
+                _inBytesPacket = (_inBuff[_inBytesUsed + TdsEnums.HEADER_LEN_FIELD_OFFSET] << 8 |
+                                              _inBuff[_inBytesUsed + TdsEnums.HEADER_LEN_FIELD_OFFSET + 1]) - _inputHeaderLen;
+                _spid = _inBuff[_inBytesUsed + TdsEnums.SPID_OFFSET] << 8 |
+                                              _inBuff[_inBytesUsed + TdsEnums.SPID_OFFSET + 1];
+#if !NETFRAMEWORK
+                SqlClientEventSource.Log.TryAdvancedTraceEvent("TdsParserStateObject.TryProcessHeader | ADV | State Object Id {0}, Client Connection Id {1}, Server process Id (SPID) {2}", _objectID, _parser?.Connection?.ClientConnectionId, _spid);
+#endif
+                _inBytesUsed += _inputHeaderLen;
+
+                AssertValidState();
+            }
+
+            if (_inBytesPacket < 0)
+            {
+#if NETFRAMEWORK
+                throw SQL.ParsingError(ParsingErrorState.CorruptedTdsStream);
+#else
+                // either TDS stream is corrupted or there is multithreaded misuse of connection
+                throw SQL.ParsingError();
+#endif
+            }
+
+            return true;
+        }
+
+        // This ensure that there is data available to be read in the buffer and that the header has been processed
+        // NOTE: This method (and all it calls) should be retryable without replaying a snapshot
+        internal bool TryPrepareBuffer()
+        {
+#if NETFRAMEWORK
+            TdsParser.ReliabilitySection.Assert("unreliable call to ReadBuffer");  // you need to setup for a thread abort somewhere before you call this method
+#endif
+            Debug.Assert(_inBuff != null, "packet buffer should not be null!");
+
+            // Header spans packets, or we haven't read the header yet - process header
+            if ((_inBytesPacket == 0) && (_inBytesUsed < _inBytesRead))
+            {
+                if (!TryProcessHeader())
+                {
+                    return false;
+                }
+                Debug.Assert(_inBytesPacket != 0, "_inBytesPacket cannot be 0 after processing header!");
+                AssertValidState();
+            }
+
+            // If we're out of data, need to read more
+            if (_inBytesUsed == _inBytesRead)
+            {
+                // If the _inBytesPacket is not zero, then we have data left in the packet, but the data in the packet
+                // spans the buffer, so we can read any amount of data possible, and we do not need to call ProcessHeader
+                // because there isn't a header at the beginning of the data that we are reading.
+                if (_inBytesPacket > 0)
+                {
+                    if (!TryReadNetworkPacket())
+                    {
+                        return false;
+                    }
+                }
+                else if (_inBytesPacket == 0)
+                {
+                    // Else we have finished the packet and so we must read as much data as possible
+                    if (!TryReadNetworkPacket())
+                    {
+                        return false;
+                    }
+
+                    if (!TryProcessHeader())
+                    {
+                        return false;
+                    }
+
+                    Debug.Assert(_inBytesPacket != 0, "_inBytesPacket cannot be 0 after processing header!");
+                    if (_inBytesUsed == _inBytesRead)
+                    {
+                        // we read a header but didn't get anything else except it
+                        // VSTS 219884: it can happen that the TDS packet header and its data are split across two network packets.
+                        // Read at least one more byte to get/cache the first data portion of this TDS packet
+                        if (!TryReadNetworkPacket())
+                        {
+                            return false;
+                        }
+                    }
+                }
+                else
+                {
+                    Debug.Fail("entered negative _inBytesPacket loop");
+                }
+                AssertValidState();
+            }
+
+            return true;
+        }
+
+        internal void ResetBuffer()
+        {
+            _outBytesUsed = _outputHeaderLen;
+        }
+
+        internal void ResetPacketCounters()
+        {
+            _outputPacketNumber = 1;
+            _outputPacketCount = 0;
+        }
+        
+        internal bool SetPacketSize(int size)
+        {
+            if (size > TdsEnums.MAX_PACKET_SIZE)
+            {
+                throw SQL.InvalidPacketSize();
+            }
+            Debug.Assert(size >= 1, "Cannot set packet size to less than 1.");
+            Debug.Assert((_outBuff == null && _inBuff == null) ||
+                          (_outBuff.Length == _inBuff.Length),
+                          "Buffers are not in consistent state");
+            Debug.Assert((_outBuff == null && _inBuff == null) ||
+                          this == _parser._physicalStateObj,
+                          "SetPacketSize should only be called on a stateObj with null buffers on the physicalStateObj!");
+            Debug.Assert(_inBuff == null
+                          ||
+                          (
+                          _parser.Is2005OrNewer &&
+                           _outBytesUsed == (_outputHeaderLen + BitConverter.ToInt32(_outBuff, _outputHeaderLen)) &&
+                           _outputPacketNumber == 1)
+                          ||
+                          (_outBytesUsed == _outputHeaderLen && _outputPacketNumber == 1),
+                          "SetPacketSize called with data in the buffer!");
+
+            if (_inBuff == null || _inBuff.Length != size)
+            { // We only check _inBuff, since two buffers should be consistent.
+                // Allocate or re-allocate _inBuff.
+                if (_inBuff == null)
+                {
+                    _inBuff = new byte[size];
+                    _inBytesRead = 0;
+                    _inBytesUsed = 0;
+                }
+                else if (size != _inBuff.Length)
+                {
+                    // If new size is other than existing...
+                    if (_inBytesRead > _inBytesUsed)
+                    {
+                        // if we still have data left in the buffer we must keep that array reference and then copy into new one
+                        byte[] temp = _inBuff;
+
+                        _inBuff = new byte[size];
+
+                        // copy remainder of unused data
+                        int remainingData = _inBytesRead - _inBytesUsed;
+                        if ((temp.Length < _inBytesUsed + remainingData) || (_inBuff.Length < remainingData))
+                        {
+                            string errormessage = StringsHelper.GetString(Strings.SQL_InvalidInternalPacketSize) + ' ' + temp.Length + ", " + _inBytesUsed + ", " + remainingData + ", " + _inBuff.Length;
+                            throw SQL.InvalidInternalPacketSize(errormessage);
+                        }
+                        Buffer.BlockCopy(temp, _inBytesUsed, _inBuff, 0, remainingData);
+
+                        _inBytesRead = _inBytesRead - _inBytesUsed;
+                        _inBytesUsed = 0;
+
+                        AssertValidState();
+                    }
+                    else
+                    {
+                        // buffer is empty - just create the new one that is double the size of the old one
+                        _inBuff = new byte[size];
+                        _inBytesRead = 0;
+                        _inBytesUsed = 0;
+                    }
+                }
+
+                // Always re-allocate _outBuff - assert is above to verify state.
+                _outBuff = new byte[size];
+                _outBytesUsed = _outputHeaderLen;
+
+                AssertValidState();
+                return true;
+            }
+
+            return false;
+        }
+        /*
+
+        // leave this in. comes handy if you have to do Console.WriteLine style debugging ;)
+        private void DumpBuffer() {
+            Console.WriteLine("dumping buffer");
+            Console.WriteLine("_inBytesRead = {0}", _inBytesRead);
+            Console.WriteLine("_inBytesUsed = {0}", _inBytesUsed);
+            int cc = 0; // character counter
+            int i;
+            Console.WriteLine("used buffer:");
+            for (i=0; i< _inBytesUsed; i++) {
+                if (cc==16) {
+                    Console.WriteLine();
+                    cc = 0;
+                }
+                Console.Write("{0,-2:X2} ", _inBuff[i]);
+                cc++;
+            }
+            if (cc>0) {
+                Console.WriteLine();
+            }
+
+            cc = 0;
+            Console.WriteLine("unused buffer:");
+            for (i=_inBytesUsed; i<_inBytesRead; i++) {
+                if (cc==16) {
+                    Console.WriteLine();
+                    cc = 0;
+                }
+                Console.Write("{0,-2:X2} ", _inBuff[i]);
+                cc++;
+            }
+            if (cc>0) {
+                Console.WriteLine();
+            }
+        }
+        */
+    }
+}