throw correct exception failed writes

1 files changed, 30 insertions, 2 deletions

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
             {