WriteAsync cancellation throws an error with the calls completed status if possible

src/Grpc.Net.Client/Internal/GrpcCall.NonGeneric.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -53,6 +53,7 @@ public DefaultDeserializationContext DeserializationContext
 
     public string? RequestGrpcEncoding { get; internal set; }
 
+    public abstract Task<Status> CallTask { get; }
     public abstract CancellationToken CancellationToken { get; }
     public abstract Type RequestType { get; }
     public abstract Type ResponseType { get; }
@@ -64,6 +65,29 @@ protected GrpcCall(CallOptions options, GrpcChannel channel)
         Logger = channel.LoggerFactory.CreateLogger(LoggerName);
     }
 
+    public Exception CreateCanceledStatusException(Exception? ex = null)
+    {
+        var status = (CallTask.IsCompletedSuccessfully()) ? CallTask.Result : new Status(StatusCode.Cancelled, string.Empty, ex);
+        return CreateRpcException(status);
+    }
+
+    public CancellationToken GetCanceledToken(CancellationToken methodCancellationToken)
+    {
+        if (methodCancellationToken.IsCancellationRequested)
+        {
+            return methodCancellationToken;
+        }
+        else if (Options.CancellationToken.IsCancellationRequested)
+        {
+            return Options.CancellationToken;
+        }
+        else if (CancellationToken.IsCancellationRequested)
+        {
+            return CancellationToken;
+        }
+        return CancellationToken.None;
+    }
+
     internal RpcException CreateRpcException(Status status)
     {
         // This code can be called from a background task.
@@ -84,6 +108,23 @@ internal RpcException CreateRpcException(Status status)
         return new RpcException(status, trailers ?? Metadata.Empty);
     }
 
+    public Exception CreateFailureStatusException(Status status)
+    {
+        if (Channel.ThrowOperationCanceledOnCancellation &&
+            (status.StatusCode == StatusCode.DeadlineExceeded || status.StatusCode == StatusCode.Cancelled))
+        {
+            // Convert status response of DeadlineExceeded to OperationCanceledException when
+            // ThrowOperationCanceledOnCancellation is true.
+            // This avoids a race between the client-side timer and the server status throwing different
+            // errors on deadline exceeded.
+            return new OperationCanceledException();
+        }
+        else
+        {
+            return CreateRpcException(status);
+        }
+    }
+
     protected bool TryGetTrailers([NotNullWhen(true)] out Metadata? trailers)
     {
         if (Trailers == null)

src/Grpc.Net.Client/Internal/GrpcCall.cs

@@ -90,7 +90,7 @@ private void ValidateDeadline(DateTime? deadline)
         }
     }
 
-    public Task<Status> CallTask => _callTcs.Task;
+    public override Task<Status> CallTask => _callTcs.Task;
 
     public override CancellationToken CancellationToken => _callCts.Token;
 
@@ -248,12 +248,6 @@ public void EnsureNotDisposed()
         }
     }
 
-    public Exception CreateCanceledStatusException(Exception? ex = null)
-    {
-        var status = (CallTask.IsCompletedSuccessfully()) ? CallTask.Result : new Status(StatusCode.Cancelled, string.Empty, ex);
-        return CreateRpcException(status);
-    }
-
     private void FinishResponseAndCleanUp(Status status)
     {
         ResponseFinished = true;
@@ -760,23 +754,6 @@ public Exception EnsureUserCancellationTokenReported(Exception ex, CancellationT
         return ex;
     }
 
-    public CancellationToken GetCanceledToken(CancellationToken methodCancellationToken)
-    {
-        if (methodCancellationToken.IsCancellationRequested)
-        {
-            return methodCancellationToken;
-        }
-        else if (Options.CancellationToken.IsCancellationRequested)
-        {
-            return Options.CancellationToken;
-        }
-        else if (CancellationToken.IsCancellationRequested)
-        {
-            return CancellationToken;
-        }
-        return CancellationToken.None;
-    }
-
     private void SetFailedResult(Status status)
     {
         CompatibilityHelpers.Assert(_responseTcs != null);
@@ -795,23 +772,6 @@ private void SetFailedResult(Status status)
         }
     }
 
-    public Exception CreateFailureStatusException(Status status)
-    {
-        if (Channel.ThrowOperationCanceledOnCancellation &&
-            (status.StatusCode == StatusCode.DeadlineExceeded || status.StatusCode == StatusCode.Cancelled))
-        {
-            // Convert status response of DeadlineExceeded to OperationCanceledException when
-            // ThrowOperationCanceledOnCancellation is true.
-            // This avoids a race between the client-side timer and the server status throwing different
-            // errors on deadline exceeded.
-            return new OperationCanceledException();
-        }
-        else
-        {
-            return CreateRpcException(status);
-        }
-    }
-
     private (bool diagnosticSourceEnabled, Activity? activity) InitializeCall(HttpRequestMessage request, TimeSpan? timeout)
     {
         GrpcCallLog.StartingCall(Logger, Method.Type, request.RequestUri!);

src/Grpc.Net.Client/Internal/Http/PushStreamContent.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -72,4 +72,10 @@ protected override bool TryComputeLength(out long length)
     // Hacky. ReadAsStreamAsync does not complete until SerializeToStreamAsync finishes.
     // WARNING: Will run SerializeToStreamAsync again on .NET Framework.
     internal Task PushComplete => ReadAsStreamAsync();
-}
+
+    // Internal for testing.
+    internal Task SerializeToStreamAsync(Stream stream)
+    {
+        return SerializeToStreamAsync(stream, context: null);
+    }
+}

src/Grpc.Net.Client/Internal/StreamExtensions.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -23,6 +23,7 @@
 using System.Runtime.InteropServices;
 using Grpc.Core;
 using Grpc.Net.Compression;
+using Grpc.Shared;
 using Microsoft.Extensions.Logging;
 
 #if NETSTANDARD2_0
@@ -318,10 +319,9 @@ public static async ValueTask WriteMessageAsync<TMessage>(
         {
             GrpcCallLog.ErrorSendingMessage(call.Logger, ex);
 
-            // Cancellation from disposing response while waiting for WriteAsync can throw ObjectDisposedException.
-            if (ex is ObjectDisposedException && call.CancellationToken.IsCancellationRequested)
+            if (TryCreateCallCompleteException(ex, call, out var statusException))
             {
-                throw new OperationCanceledException();
+                throw statusException;
             }
 
             throw;
@@ -342,24 +342,41 @@ public static async ValueTask WriteMessageAsync(
         {
             GrpcCallLog.SendingMessage(call.Logger);
 
-            try
-            {
-                // Sending the header+content in a single WriteAsync call has significant performance benefits
-                // https://github.com/dotnet/runtime/issues/35184#issuecomment-626304981
-                await stream.WriteAsync(data, cancellationToken).ConfigureAwait(false);
-            }
-            catch (ObjectDisposedException) when (call.CancellationToken.IsCancellationRequested)
-            {
-                // Cancellation from disposing response while waiting for WriteAsync can throw ObjectDisposedException.
-                throw new OperationCanceledException();
-            }
+            // Sending the header+content in a single WriteAsync call has significant performance benefits
+            // https://github.com/dotnet/runtime/issues/35184#issuecomment-626304981
+            await stream.WriteAsync(data, cancellationToken).ConfigureAwait(false);
 
             GrpcCallLog.MessageSent(call.Logger);
         }
         catch (Exception ex)
         {
             GrpcCallLog.ErrorSendingMessage(call.Logger, ex);
+
+            if (TryCreateCallCompleteException(ex, call, out var statusException))
+            {
+                throw statusException;
+            }
+
             throw;
         }
     }
+
+    private static bool TryCreateCallCompleteException(Exception originalException, GrpcCall call, [NotNullWhen(true)] out Exception? exception)
+    {
+        // The call may have been completed while WriteAsync was running and caused WriteAsync to throw.
+        // In this situation, report the call's completed status.
+        //
+        // Replace exception with the status error if:
+        // 1. The original exception is one Stream.WriteAsync throws if the call was completed during a write, and
+        // 2. The call has already been successfully completed.
+        if (originalException is OperationCanceledException or ObjectDisposedException &&
+            call.CallTask.IsCompletedSuccessfully())
+        {
+            exception = call.CreateFailureStatusException(call.CallTask.Result);
+            return true;
+        }
+
+        exception = null;
+        return false;
+    }
 }

test/FunctionalTests/Client/StreamingTests.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //

test/Grpc.Net.Client.Tests/AsyncClientStreamingCallTests.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -107,7 +107,6 @@ public async Task AsyncClientStreamingCall_Success_RequestContentSent()
         var responseTask = call.ResponseAsync;
         Assert.IsFalse(responseTask.IsCompleted, "Response not returned until client stream is complete.");
 
-
         await call.RequestStream.WriteAsync(new HelloRequest { Name = "1" }).DefaultTimeout();
         await call.RequestStream.WriteAsync(new HelloRequest { Name = "2" }).DefaultTimeout();
 
@@ -268,6 +267,106 @@ public async Task ClientStreamWriter_WriteAfterResponseHasFinished_ErrorThrown()
         Assert.AreEqual("Hello world", result.Message);
     }
 
+    [Test]
+    public async Task AsyncClientStreamingCall_ErrorWhileWriting_StatusExceptionThrown()
+    {
+        // Arrange
+        PushStreamContent<HelloRequest, HelloReply>? content = null;
+
+        var responseTcs = new TaskCompletionSource<HttpResponseMessage>(TaskCreationOptions.RunContinuationsAsynchronously);
+        var httpClient = ClientTestHelpers.CreateTestClient(request =>
+        {
+            content = (PushStreamContent<HelloRequest, HelloReply>)request.Content!;
+            return responseTcs.Task;
+        });
+
+        var invoker = HttpClientCallInvokerFactory.Create(httpClient);
+
+        // Act
+
+        // Client starts call
+        var call = invoker.AsyncClientStreamingCall<HelloRequest, HelloReply>(ClientTestHelpers.ServiceMethod, string.Empty, new CallOptions());
+        // Client starts request stream write
+        var writeTask = call.RequestStream.WriteAsync(new HelloRequest());
+
+        // Simulate HttpClient starting to accept the write. Stream.WriteAsync is blocked.
+        var writeSyncPoint = new SyncPoint(runContinuationsAsynchronously: true);
+        var testStream = new TestStream(writeSyncPoint);
+        var serializeToStreamTask = content!.SerializeToStreamAsync(testStream);
+
+        // Server completes response.
+        await writeSyncPoint.WaitForSyncPoint().DefaultTimeout();
+        responseTcs.SetResult(ResponseUtils.CreateResponse(HttpStatusCode.OK, new ByteArrayContent(Array.Empty<byte>()), grpcStatusCode: StatusCode.InvalidArgument));
+
+        await ExceptionAssert.ThrowsAsync<RpcException>(() => call.ResponseAsync).DefaultTimeout();
+        Assert.AreEqual(StatusCode.InvalidArgument, call.GetStatus().StatusCode);
+
+        // Unblock Stream.WriteAsync
+        writeSyncPoint.Continue();
+
+        // Get error thrown from write task. It should have the status returned by the server.
+        var ex = await ExceptionAssert.ThrowsAsync<RpcException>(() => writeTask).DefaultTimeout();
+
+        // Assert
+        Assert.AreEqual(StatusCode.InvalidArgument, ex.StatusCode);
+        Assert.AreEqual(StatusCode.InvalidArgument, call.GetStatus().StatusCode);
+        Assert.AreEqual(string.Empty, call.GetStatus().Detail);
+    }
+
+    private sealed class TestStream : Stream
+    {
+        private readonly SyncPoint _writeSyncPoint;
+
+        public TestStream(SyncPoint writeSyncPoint)
+        {
+            _writeSyncPoint = writeSyncPoint;
+        }
+
+        public override bool CanRead { get; }
+        public override bool CanSeek { get; }
+        public override bool CanWrite { get; }
+        public override long Length { get; }
+        public override long Position { get; set; }
+
+        public override void Flush()
+        {
+        }
+
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override void SetLength(long value)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            throw new NotImplementedException();
+        }
+
+#if !NET472_OR_GREATER
+        public override async ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = default)
+        {
+            await _writeSyncPoint.WaitToContinue();
+            throw new OperationCanceledException();
+        }
+#else
+        public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            await _writeSyncPoint.WaitToContinue();
+            throw new OperationCanceledException();
+        }
+#endif
+    }
+
     [Test]
     public async Task ClientStreamWriter_CancelledBeforeCallStarts_ThrowsError()
     {

test/Grpc.Net.Client.Tests/GrpcCallSerializationContextTests.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -318,6 +318,7 @@ public TestGrpcCall(CallOptions options, GrpcChannel channel) : base(options, ch
         public override Type RequestType { get; } = typeof(int);
         public override Type ResponseType { get; } = typeof(string);
         public override CancellationToken CancellationToken { get; }
+        public override Task<Status> CallTask => Task.FromResult(Status.DefaultCancelled);
     }
 
     private GrpcCallSerializationContext CreateSerializationContext(string? requestGrpcEncoding = null, int? maxSendMessageSize = null)

test/Grpc.Net.Client.Tests/Infrastructure/StreamSerializationHelper.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -65,5 +65,6 @@ public TestGrpcCall(CallOptions options, GrpcChannel channel, Type type) : base(
         public override Type RequestType => _type;
         public override Type ResponseType => _type;
         public override CancellationToken CancellationToken { get; }
+        public override Task<Status> CallTask => Task.FromResult(Status.DefaultCancelled);
     }
 }