3 files changed, 56 insertions, 4 deletions
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCall.cs b/src/csharp/Grpc.Core/Internal/AsyncCall.cs
index f549c52876..db40b553ce 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCall.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCall.cs
@@ -341,6 +341,11 @@ namespace Grpc.Core.Internal
             get { return true; }
         }
 
+        protected override Exception GetRpcExceptionClientOnly()
+        {
+            return new RpcException(finishedStatus.Value.Status);
+        }
+
         protected override Task CheckSendAllowedOrEarlyResult()
         {
             var earlyResult = CheckSendPreconditionsClientSide();
@@ -452,6 +457,7 @@ namespace Grpc.Core.Internal
 
             using (Profilers.ForCurrentThread().NewScope("AsyncCall.HandleUnaryResponse"))
             {
+                TaskCompletionSource<object> delayedTcs;
                 TResponse msg = default(TResponse);
                 var deserializeException = TryDeserialize(receivedMessage, out msg);
 
@@ -464,14 +470,19 @@ namespace Grpc.Core.Internal
                         receivedStatus = new ClientSideStatus(DeserializeResponseFailureStatus, receivedStatus.Trailers);
                     }
                     finishedStatus = receivedStatus;
+                    delayedTcs = delayedStreamingWriteTcs;
 
                     ReleaseResourcesIfPossible();
                 }
 
                 responseHeadersTcs.SetResult(responseHeaders);
 
-                var status = receivedStatus.Status;
+                if (delayedTcs != null)
+                {
+                    delayedTcs.SetException(GetRpcExceptionClientOnly());
+                }
 
+                var status = receivedStatus.Status;
                 if (status.StatusCode != StatusCode.OK)
                 {
                     unaryResponseTcs.SetException(new RpcException(status));
@@ -490,16 +501,23 @@ namespace Grpc.Core.Internal
             // NOTE: because this event is a result of batch containing GRPC_OP_RECV_STATUS_ON_CLIENT,
             // success will be always set to true.
 
+            TaskCompletionSource<object> delayedTcs;
+
             lock (myLock)
             {
                 finished = true;
                 finishedStatus = receivedStatus;
+                delayedTcs = delayedStreamingWriteTcs;
 
                 ReleaseResourcesIfPossible();
             }
 
-            var status = receivedStatus.Status;
+            if (delayedTcs != null)
+            {
+                delayedTcs.SetException(GetRpcExceptionClientOnly());
+            }
 
+            var status = receivedStatus.Status;
             if (status.StatusCode != StatusCode.OK)
             {
                 streamingCallFinishedTcs.SetException(new RpcException(status));
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs b/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
index eb9c3ea62d..b27baba942 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
@@ -68,6 +68,7 @@ namespace Grpc.Core.Internal
 
         protected TaskCompletionSource<TRead> streamingReadTcs;  // Completion of a pending streaming read if not null.
         protected TaskCompletionSource<object> streamingWriteTcs;  // Completion of a pending streaming write or send close from client if not null.
+        protected TaskCompletionSource<object> delayedStreamingWriteTcs;
         protected TaskCompletionSource<object> sendStatusFromServerTcs;
 
         protected bool readingDone;  // True if last read (i.e. read with null payload) was already received.
@@ -200,6 +201,12 @@ namespace Grpc.Core.Internal
             get;
         }
 
+        /// <summary>
+        /// Returns an exception to throw for a failed send operation.
+        /// It is only allowed to call this method for a call that has already finished.
+        /// </summary>
+        protected abstract Exception GetRpcExceptionClientOnly();
+
         private void ReleaseResources()
         {
             if (call != null)
@@ -252,18 +259,39 @@ namespace Grpc.Core.Internal
         /// </summary>
         protected void HandleSendFinished(bool success)
         {
+            bool delayCompletion = false;
             TaskCompletionSource<object> origTcs = null;
             lock (myLock)
             {
                 origTcs = streamingWriteTcs;
                 streamingWriteTcs = null;
 
+                if (!success && !finished && IsClient)
+                {
+                    // We should be setting this only once per call, following writes will be short circuited.
+                    GrpcPreconditions.CheckState (delayedStreamingWriteTcs == null);
+                    delayedStreamingWriteTcs = origTcs;
+                    delayCompletion = true;
+                }
+
                 ReleaseResourcesIfPossible();
             }
 
             if (!success)
             {
-                origTcs.SetException(new InvalidOperationException("Send failed"));
+                if (!delayCompletion)
+                {
+                    if (IsClient)
+                    {
+                        GrpcPreconditions.CheckState(finished);  // implied by !success && !delayCompletion && IsClient
+                        origTcs.SetException(GetRpcExceptionClientOnly());
+                    }
+                    else
+                    {
+                        origTcs.SetException (new IOException("Error sending from server."));
+                    }
+                }
+                // if delayCompletion == true, postpone SetException until call finishes.
             }
             else
             {
@@ -283,7 +311,7 @@ namespace Grpc.Core.Internal
 
             if (!success)
             {
-                sendStatusFromServerTcs.SetException(new InvalidOperationException("Error sending status from server."));
+                sendStatusFromServerTcs.SetException(new IOException("Error sending status from server."));
             }
             else
             {
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs b/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
index 56c23ba3ef..50fdfa9006 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
@@ -33,6 +33,7 @@
 
 using System;
 using System.Diagnostics;
+using System.IO;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Threading;
@@ -193,6 +194,11 @@ namespace Grpc.Core.Internal
             get { return false; }
         }
 
+        protected override Exception GetRpcExceptionClientOnly()
+        {
+            throw new InvalidOperationException("Call be only called for client calls");
+        }
+
         protected override void OnAfterReleaseResources()
         {
             server.RemoveCallReference(this);