improve unary call response handler

src/csharp/Grpc.Core/Internal/AsyncCall.cs

@@ -407,12 +407,15 @@ namespace Grpc.Core.Internal
         /// <summary>
         /// Handler for unary response completion.
         /// </summary>
-        private void HandleUnaryResponse(bool success, ClientSideStatus receivedStatus, byte[] receivedMessage, Metadata responseHeaders)
+        private void HandleUnaryResponse(bool sucess, ClientSideStatus receivedStatus, byte[] receivedMessage, Metadata responseHeaders)
         {
+            // NOTE: because this event is a result of batch containing GRPC_OP_RECV_STATUS_ON_CLIENT,
+            // success will be always set to true.
+
             using (Profilers.ForCurrentThread().NewScope("AsyncCall.HandleUnaryResponse"))
             {
                 TResponse msg = default(TResponse);
-                var deserializeException = success ? TryDeserialize(receivedMessage, out msg) : null;
+                var deserializeException = TryDeserialize(receivedMessage, out msg);
 
                 lock (myLock)
                 {
@@ -425,14 +428,13 @@ namespace Grpc.Core.Internal
                     finishedStatus = receivedStatus;
 
                     ReleaseResourcesIfPossible();
-
                 }
 
                 responseHeadersTcs.SetResult(responseHeaders);
 
                 var status = receivedStatus.Status;
 
-                if (!success || status.StatusCode != StatusCode.OK)
+                if (status.StatusCode != StatusCode.OK)
                 {
                     unaryResponseTcs.SetException(new RpcException(status));
                     return;
@@ -447,6 +449,9 @@ namespace Grpc.Core.Internal
         /// </summary>
         private void HandleFinished(bool success, ClientSideStatus receivedStatus)
         {
+            // NOTE: because this event is a result of batch containing GRPC_OP_RECV_STATUS_ON_CLIENT,
+            // success will be always set to true.
+
             lock (myLock)
             {
                 finished = true;
@@ -457,7 +462,7 @@ namespace Grpc.Core.Internal
 
             var status = receivedStatus.Status;
 
-            if (!success || status.StatusCode != StatusCode.OK)
+            if (status.StatusCode != StatusCode.OK)
             {
                 streamingCallFinishedTcs.SetException(new RpcException(status));
                 return;