[Release 5.0] Fix async deadlock issue when sending attention fails due to network failure

cheenamalhotra · cheenamalhotra · commit 8ae26ab71e5e · 2022-10-04T09:34:24.000-07:00
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
@@ -55,7 +55,7 @@ public TimeoutState(int value)
 
         private const int AttentionTimeoutSeconds = 5;
 
-        private static readonly ContextCallback s_readAdyncCallbackComplete = ReadAsyncCallbackComplete;
+        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.
@@ -2337,9 +2337,9 @@ private void OnTimeoutAsync(object state)
             }
         }
 
-        private bool OnTimeoutSync()
+        private bool OnTimeoutSync(bool asyncClose = false)
         {
-            return OnTimeoutCore(TimeoutState.Running, TimeoutState.ExpiredSync);
+            return OnTimeoutCore(TimeoutState.Running, TimeoutState.ExpiredSync, asyncClose);
         }
 
         /// <summary>
@@ -2348,8 +2348,9 @@ private bool OnTimeoutSync()
         /// </summary>
         /// <param name="expectedState">the state that is the expected current state, state will change only if this is correct</param>
         /// <param name="targetState">the state that will be changed to if the expected state is correct</param>
+        /// <param name="asyncClose">any close action to be taken by an async task to avoid deadlock.</param>
         /// <returns>boolean value indicating whether the call changed the timeout state</returns>
-        private bool OnTimeoutCore(int expectedState, int targetState)
+        private bool OnTimeoutCore(int expectedState, int targetState, bool asyncClose = false)
         {
             Debug.Assert(targetState == TimeoutState.ExpiredAsync || targetState == TimeoutState.ExpiredSync, "OnTimeoutCore must have an expiry state as the targetState");
 
@@ -2382,7 +2383,7 @@ private bool OnTimeoutCore(int expectedState, int targetState)
                         {
                             try
                             {
-                                SendAttention(mustTakeWriteLock: true);
+                                SendAttention(mustTakeWriteLock: true, asyncClose);
                             }
                             catch (Exception e)
                             {
@@ -2927,7 +2928,7 @@ public void ReadAsyncCallback(IntPtr key, PacketHandle packet, uint error)
                 // synchrnously and then call OnTimeoutSync to force an atomic change of state. 
                 if (TimeoutHasExpired)
                 {
-                    OnTimeoutSync();
+                    OnTimeoutSync(true);
                 }
 
                 // try to change to the stopped state but only do so if currently in the running state
@@ -2958,7 +2959,7 @@ public void ReadAsyncCallback(IntPtr key, PacketHandle packet, uint error)
                     {
                         if (_executionContext != null)
                         {
-                            ExecutionContext.Run(_executionContext, s_readAdyncCallbackComplete, source);
+                            ExecutionContext.Run(_executionContext, s_readAsyncCallbackComplete, source);
                         }
                         else
                         {
@@ -3441,7 +3442,7 @@ private void CancelWritePacket()
 
 #pragma warning disable 0420 // a reference to a volatile field will not be treated as volatile
 
-        private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccumulate, bool callerHasConnectionLock)
+        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);
@@ -3534,7 +3535,7 @@ private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccu
                         {
                             SqlClientEventSource.Log.TryTraceEvent("TdsParserStateObject.SNIWritePacket | Info | State Object Id {0}, Write async returned error code {1}", _objectID, (int)error);
                             AddError(_parser.ProcessSNIError(this));
-                            ThrowExceptionAndWarning();
+                            ThrowExceptionAndWarning(false, asyncClose);
                         }
                         AssertValidState();
                         completion.SetResult(null);
@@ -3569,7 +3570,7 @@ private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccu
                 {
                     SqlClientEventSource.Log.TryTraceEvent("TdsParserStateObject.SNIWritePacket | Info | State Object Id {0}, Write async returned error code {1}", _objectID, (int)sniError);
                     AddError(_parser.ProcessSNIError(this));
-                    ThrowExceptionAndWarning(callerHasConnectionLock);
+                    ThrowExceptionAndWarning(callerHasConnectionLock, asyncClose);
                 }
                 AssertValidState();
             }
@@ -3581,7 +3582,7 @@ private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccu
         internal abstract uint WritePacket(PacketHandle packet, bool sync);
 
         // Sends an attention signal - executing thread will consume attn.
-        internal void SendAttention(bool mustTakeWriteLock = false)
+        internal void SendAttention(bool mustTakeWriteLock = false, bool asyncClose = false)
         {
             if (!_attentionSent)
             {
@@ -3623,7 +3624,7 @@ internal void SendAttention(bool mustTakeWriteLock = false)
 
                             uint sniError;
                             _parser._asyncWrite = false; // stop async write
-                            SNIWritePacket(attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false);
+                            SNIWritePacket(attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false, asyncClose);
                             SqlClientEventSource.Log.TryTraceEvent("TdsParserStateObject.SendAttention | Info | State Object Id {0}, Sent Attention.", _objectID);
                         }
                         finally
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
@@ -2401,9 +2401,9 @@ private void OnTimeoutAsync(object state)
             }
         }
 
-        private bool OnTimeoutSync()
+        private bool OnTimeoutSync(bool asyncClose = false)
         {
-            return OnTimeoutCore(TimeoutState.Running, TimeoutState.ExpiredSync);
+            return OnTimeoutCore(TimeoutState.Running, TimeoutState.ExpiredSync, asyncClose);
         }
 
         /// <summary>
@@ -2412,8 +2412,9 @@ private bool OnTimeoutSync()
         /// </summary>
         /// <param name="expectedState">the state that is the expected current state, state will change only if this is correct</param>
         /// <param name="targetState">the state that will be changed to if the expected state is correct</param>
+        /// <param name="asyncClose">any close action to be taken by an async task to avoid deadlock.</param>
         /// <returns>boolean value indicating whether the call changed the timeout state</returns>
-        private bool OnTimeoutCore(int expectedState, int targetState)
+        private bool OnTimeoutCore(int expectedState, int targetState, bool asyncClose = false)
         {
             Debug.Assert(targetState == TimeoutState.ExpiredAsync || targetState == TimeoutState.ExpiredSync, "OnTimeoutCore must have an expiry state as the targetState");
 
@@ -2447,7 +2448,7 @@ private bool OnTimeoutCore(int expectedState, int targetState)
                         {
                             try
                             {
-                                SendAttention(mustTakeWriteLock: true);
+                                SendAttention(mustTakeWriteLock: true, asyncClose);
                             }
                             catch (Exception e)
                             {
@@ -2988,7 +2989,7 @@ public void ReadAsyncCallback(IntPtr key, IntPtr packet, UInt32 error)
                 // synchrnously and then call OnTimeoutSync to force an atomic change of state.
                 if (TimeoutHasExpired)
                 {
-                    OnTimeoutSync();
+                    OnTimeoutSync(asyncClose: true);
                 }
 
                 // try to change to the stopped state but only do so if currently in the running state
@@ -3475,7 +3476,7 @@ 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)
+        private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniError, bool canAccumulate, bool callerHasConnectionLock, bool asyncClose = false)
         {
             // Check for a stored exception
             var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);
@@ -3566,7 +3567,7 @@ private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniEr
                             SqlClientEventSource.Log.TryTraceEvent("<sc.TdsParser.WritePacket|Info> write async returned error code {0}", (int)error);
 
                             AddError(_parser.ProcessSNIError(this));
-                            ThrowExceptionAndWarning();
+                            ThrowExceptionAndWarning(false, asyncClose);
                         }
                         AssertValidState();
                         completion.SetResult(null);
@@ -3603,7 +3604,7 @@ private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniEr
                 {
                     SqlClientEventSource.Log.TryTraceEvent("<sc.TdsParser.WritePacket|Info> write async returned error code {0}", (int)sniError);
                     AddError(_parser.ProcessSNIError(this));
-                    ThrowExceptionAndWarning(callerHasConnectionLock);
+                    ThrowExceptionAndWarning(callerHasConnectionLock, false);
                 }
                 AssertValidState();
             }
@@ -3613,7 +3614,7 @@ private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniEr
 #pragma warning restore 420 
 
         // Sends an attention signal - executing thread will consume attn.
-        internal void SendAttention(bool mustTakeWriteLock = false)
+        internal void SendAttention(bool mustTakeWriteLock = false, bool asyncClose = false)
         {
             if (!_attentionSent)
             {
@@ -3660,7 +3661,7 @@ internal void SendAttention(bool mustTakeWriteLock = false)
 
                             UInt32 sniError;
                             _parser._asyncWrite = false; // stop async write 
-                            SNIWritePacket(Handle, attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false);
+                            SNIWritePacket(Handle, attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false, asyncClose);
                             SqlClientEventSource.Log.TryTraceEvent("<sc.TdsParser.SendAttention|{0}> Send Attention ASync.", "Info");
                         }
                         finally

Original file line number	Diff line number	Diff line change
`@@ -55,7 +55,7 @@ public TimeoutState(int value)`
`55`	`55`
`56`	`56`	`private const int AttentionTimeoutSeconds = 5;`
`57`	`57`
`58`		`- private static readonly ContextCallback s_readAdyncCallbackComplete = ReadAsyncCallbackComplete;`
	`58`	`+ private static readonly ContextCallback s_readAsyncCallbackComplete = ReadAsyncCallbackComplete;`
`59`	`59`
`60`	`60`	`// Ticks to consider a connection "good" after a successful I/O (10,000 ticks = 1 ms)`
`61`	`61`	`// The resolution of the timer is typically in the range 10 to 16 milliseconds according to msdn.`
`@@ -2337,9 +2337,9 @@ private void OnTimeoutAsync(object state)`
`2337`	`2337`	`}`
`2338`	`2338`	`}`
`2339`	`2339`
`2340`		`- private bool OnTimeoutSync()`
	`2340`	`+ private bool OnTimeoutSync(bool asyncClose = false)`
`2341`	`2341`	`{`
`2342`		`- return OnTimeoutCore(TimeoutState.Running, TimeoutState.ExpiredSync);`
	`2342`	`+ return OnTimeoutCore(TimeoutState.Running, TimeoutState.ExpiredSync, asyncClose);`
`2343`	`2343`	`}`
`2344`	`2344`
`2345`	`2345`	`/// <summary>`
`@@ -2348,8 +2348,9 @@ private bool OnTimeoutSync()`
`2348`	`2348`	`/// </summary>`
`2349`	`2349`	`/// <param name="expectedState">the state that is the expected current state, state will change only if this is correct</param>`
`2350`	`2350`	`/// <param name="targetState">the state that will be changed to if the expected state is correct</param>`
	`2351`	`+ /// <param name="asyncClose">any close action to be taken by an async task to avoid deadlock.</param>`
`2351`	`2352`	`/// <returns>boolean value indicating whether the call changed the timeout state</returns>`
`2352`		`- private bool OnTimeoutCore(int expectedState, int targetState)`
	`2353`	`+ private bool OnTimeoutCore(int expectedState, int targetState, bool asyncClose = false)`
`2353`	`2354`	`{`
`2354`	`2355`	`Debug.Assert(targetState == TimeoutState.ExpiredAsync \|\| targetState == TimeoutState.ExpiredSync, "OnTimeoutCore must have an expiry state as the targetState");`
`2355`	`2356`
`@@ -2382,7 +2383,7 @@ private bool OnTimeoutCore(int expectedState, int targetState)`
`2382`	`2383`	`{`
`2383`	`2384`	`try`
`2384`	`2385`	`{`
`2385`		`- SendAttention(mustTakeWriteLock: true);`
	`2386`	`+ SendAttention(mustTakeWriteLock: true, asyncClose);`
`2386`	`2387`	`}`
`2387`	`2388`	`catch (Exception e)`
`2388`	`2389`	`{`
`@@ -2927,7 +2928,7 @@ public void ReadAsyncCallback(IntPtr key, PacketHandle packet, uint error)`
`2927`	`2928`	`// synchrnously and then call OnTimeoutSync to force an atomic change of state.`
`2928`	`2929`	`if (TimeoutHasExpired)`
`2929`	`2930`	`{`
`2930`		`- OnTimeoutSync();`
	`2931`	`+ OnTimeoutSync(true);`
`2931`	`2932`	`}`
`2932`	`2933`
`2933`	`2934`	`// try to change to the stopped state but only do so if currently in the running state`
`@@ -2958,7 +2959,7 @@ public void ReadAsyncCallback(IntPtr key, PacketHandle packet, uint error)`
`2958`	`2959`	`{`
`2959`	`2960`	`if (_executionContext != null)`
`2960`	`2961`	`{`
`2961`		`- ExecutionContext.Run(_executionContext, s_readAdyncCallbackComplete, source);`
	`2962`	`+ ExecutionContext.Run(_executionContext, s_readAsyncCallbackComplete, source);`
`2962`	`2963`	`}`
`2963`	`2964`	`else`
`2964`	`2965`	`{`
`@@ -3441,7 +3442,7 @@ private void CancelWritePacket()`
`3441`	`3442`
`3442`	`3443`	`#pragma warning disable 0420 // a reference to a volatile field will not be treated as volatile`
`3443`	`3444`
`3444`		`- private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccumulate, bool callerHasConnectionLock)`
	`3445`	`+ private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccumulate, bool callerHasConnectionLock, bool asyncClose = false)`
`3445`	`3446`	`{`
`3446`	`3447`	`// Check for a stored exception`
`3447`	`3448`	`var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);`
`@@ -3534,7 +3535,7 @@ private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccu`
`3534`	`3535`	`{`
`3535`	`3536`	`SqlClientEventSource.Log.TryTraceEvent("TdsParserStateObject.SNIWritePacket \| Info \| State Object Id {0}, Write async returned error code {1}", _objectID, (int)error);`
`3536`	`3537`	`AddError(_parser.ProcessSNIError(this));`
`3537`		`- ThrowExceptionAndWarning();`
	`3538`	`+ ThrowExceptionAndWarning(false, asyncClose);`
`3538`	`3539`	`}`
`3539`	`3540`	`AssertValidState();`
`3540`	`3541`	`completion.SetResult(null);`
`@@ -3569,7 +3570,7 @@ private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccu`
`3569`	`3570`	`{`
`3570`	`3571`	`SqlClientEventSource.Log.TryTraceEvent("TdsParserStateObject.SNIWritePacket \| Info \| State Object Id {0}, Write async returned error code {1}", _objectID, (int)sniError);`
`3571`	`3572`	`AddError(_parser.ProcessSNIError(this));`
`3572`		`- ThrowExceptionAndWarning(callerHasConnectionLock);`
	`3573`	`+ ThrowExceptionAndWarning(callerHasConnectionLock, asyncClose);`
`3573`	`3574`	`}`
`3574`	`3575`	`AssertValidState();`
`3575`	`3576`	`}`
`@@ -3581,7 +3582,7 @@ private Task SNIWritePacket(PacketHandle packet, out uint sniError, bool canAccu`
`3581`	`3582`	`internal abstract uint WritePacket(PacketHandle packet, bool sync);`
`3582`	`3583`
`3583`	`3584`	`// Sends an attention signal - executing thread will consume attn.`
`3584`		`- internal void SendAttention(bool mustTakeWriteLock = false)`
	`3585`	`+ internal void SendAttention(bool mustTakeWriteLock = false, bool asyncClose = false)`
`3585`	`3586`	`{`
`3586`	`3587`	`if (!_attentionSent)`
`3587`	`3588`	`{`
`@@ -3623,7 +3624,7 @@ internal void SendAttention(bool mustTakeWriteLock = false)`
`3623`	`3624`
`3624`	`3625`	`uint sniError;`
`3625`	`3626`	`_parser._asyncWrite = false; // stop async write`
`3626`		`- SNIWritePacket(attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false);`
	`3627`	`+ SNIWritePacket(attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false, asyncClose);`
`3627`	`3628`	`SqlClientEventSource.Log.TryTraceEvent("TdsParserStateObject.SendAttention \| Info \| State Object Id {0}, Sent Attention.", _objectID);`
`3628`	`3629`	`}`
`3629`	`3630`	`finally`
Original file line number	Diff line number	Diff line change
`@@ -2401,9 +2401,9 @@ private void OnTimeoutAsync(object state)`
`2401`	`2401`	`}`
`2402`	`2402`	`}`
`2403`	`2403`
`2404`		`- private bool OnTimeoutSync()`
	`2404`	`+ private bool OnTimeoutSync(bool asyncClose = false)`
`2405`	`2405`	`{`
`2406`		`- return OnTimeoutCore(TimeoutState.Running, TimeoutState.ExpiredSync);`
	`2406`	`+ return OnTimeoutCore(TimeoutState.Running, TimeoutState.ExpiredSync, asyncClose);`
`2407`	`2407`	`}`
`2408`	`2408`
`2409`	`2409`	`/// <summary>`
`@@ -2412,8 +2412,9 @@ private bool OnTimeoutSync()`
`2412`	`2412`	`/// </summary>`
`2413`	`2413`	`/// <param name="expectedState">the state that is the expected current state, state will change only if this is correct</param>`
`2414`	`2414`	`/// <param name="targetState">the state that will be changed to if the expected state is correct</param>`
	`2415`	`+ /// <param name="asyncClose">any close action to be taken by an async task to avoid deadlock.</param>`
`2415`	`2416`	`/// <returns>boolean value indicating whether the call changed the timeout state</returns>`
`2416`		`- private bool OnTimeoutCore(int expectedState, int targetState)`
	`2417`	`+ private bool OnTimeoutCore(int expectedState, int targetState, bool asyncClose = false)`
`2417`	`2418`	`{`
`2418`	`2419`	`Debug.Assert(targetState == TimeoutState.ExpiredAsync \|\| targetState == TimeoutState.ExpiredSync, "OnTimeoutCore must have an expiry state as the targetState");`
`2419`	`2420`
`@@ -2447,7 +2448,7 @@ private bool OnTimeoutCore(int expectedState, int targetState)`
`2447`	`2448`	`{`
`2448`	`2449`	`try`
`2449`	`2450`	`{`
`2450`		`- SendAttention(mustTakeWriteLock: true);`
	`2451`	`+ SendAttention(mustTakeWriteLock: true, asyncClose);`
`2451`	`2452`	`}`
`2452`	`2453`	`catch (Exception e)`
`2453`	`2454`	`{`
`@@ -2988,7 +2989,7 @@ public void ReadAsyncCallback(IntPtr key, IntPtr packet, UInt32 error)`
`2988`	`2989`	`// synchrnously and then call OnTimeoutSync to force an atomic change of state.`
`2989`	`2990`	`if (TimeoutHasExpired)`
`2990`	`2991`	`{`
`2991`		`- OnTimeoutSync();`
	`2992`	`+ OnTimeoutSync(asyncClose: true);`
`2992`	`2993`	`}`
`2993`	`2994`
`2994`	`2995`	`// try to change to the stopped state but only do so if currently in the running state`
`@@ -3475,7 +3476,7 @@ private void CancelWritePacket()`
`3475`	`3476`
`3476`	`3477`	`#pragma warning disable 420 // a reference to a volatile field will not be treated as volatile`
`3477`	`3478`
`3478`		`- private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniError, bool canAccumulate, bool callerHasConnectionLock)`
	`3479`	`+ private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniError, bool canAccumulate, bool callerHasConnectionLock, bool asyncClose = false)`
`3479`	`3480`	`{`
`3480`	`3481`	`// Check for a stored exception`
`3481`	`3482`	`var delayedException = Interlocked.Exchange(ref _delayedWriteAsyncCallbackException, null);`
`@@ -3566,7 +3567,7 @@ private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniEr`
`3566`	`3567`	`SqlClientEventSource.Log.TryTraceEvent("<sc.TdsParser.WritePacket\|Info> write async returned error code {0}", (int)error);`
`3567`	`3568`
`3568`	`3569`	`AddError(_parser.ProcessSNIError(this));`
`3569`		`- ThrowExceptionAndWarning();`
	`3570`	`+ ThrowExceptionAndWarning(false, asyncClose);`
`3570`	`3571`	`}`
`3571`	`3572`	`AssertValidState();`
`3572`	`3573`	`completion.SetResult(null);`
`@@ -3603,7 +3604,7 @@ private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniEr`
`3603`	`3604`	`{`
`3604`	`3605`	`SqlClientEventSource.Log.TryTraceEvent("<sc.TdsParser.WritePacket\|Info> write async returned error code {0}", (int)sniError);`
`3605`	`3606`	`AddError(_parser.ProcessSNIError(this));`
`3606`		`- ThrowExceptionAndWarning(callerHasConnectionLock);`
	`3607`	`+ ThrowExceptionAndWarning(callerHasConnectionLock, false);`
`3607`	`3608`	`}`
`3608`	`3609`	`AssertValidState();`
`3609`	`3610`	`}`
`@@ -3613,7 +3614,7 @@ private Task SNIWritePacket(SNIHandle handle, SNIPacket packet, out UInt32 sniEr`
`3613`	`3614`	`#pragma warning restore 420`
`3614`	`3615`
`3615`	`3616`	`// Sends an attention signal - executing thread will consume attn.`
`3616`		`- internal void SendAttention(bool mustTakeWriteLock = false)`
	`3617`	`+ internal void SendAttention(bool mustTakeWriteLock = false, bool asyncClose = false)`
`3617`	`3618`	`{`
`3618`	`3619`	`if (!_attentionSent)`
`3619`	`3620`	`{`
`@@ -3660,7 +3661,7 @@ internal void SendAttention(bool mustTakeWriteLock = false)`
`3660`	`3661`
`3661`	`3662`	`UInt32 sniError;`
`3662`	`3663`	`_parser._asyncWrite = false; // stop async write`
`3663`		`- SNIWritePacket(Handle, attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false);`
	`3664`	`+ SNIWritePacket(Handle, attnPacket, out sniError, canAccumulate: false, callerHasConnectionLock: false, asyncClose);`
`3664`	`3665`	`SqlClientEventSource.Log.TryTraceEvent("<sc.TdsParser.SendAttention\|{0}> Send Attention ASync.", "Info");`
`3665`	`3666`	`}`
`3666`	`3667`	`finally`