diff --git a/src/csharp/Grpc.Core/IAsyncStreamReader.cs b/src/csharp/Grpc.Core/IAsyncStreamReader.cs index 42bfbb87e01..4a169fcca5d 100644 --- a/src/csharp/Grpc.Core/IAsyncStreamReader.cs +++ b/src/csharp/Grpc.Core/IAsyncStreamReader.cs @@ -41,6 +41,11 @@ namespace Grpc.Core /// (MoveNext will return false) and the CancellationToken /// associated with the call will be cancelled to signal the failure. /// + /// + /// MoveNext() operations can be cancelled via a cancellation token. Cancelling + /// an individual read operation has the same effect as cancelling the entire call + /// (which will also result in the read operation returning prematurely). + /// /// /// The message type. public interface IAsyncStreamReader : IAsyncEnumerator diff --git a/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs b/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs index 851b6ca213c..ab649ee7662 100644 --- a/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs +++ b/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs @@ -49,19 +49,19 @@ namespace Grpc.Core.Internal public async Task MoveNext(CancellationToken token) { - if (token != CancellationToken.None) + var cancellationTokenRegistration = token.CanBeCanceled ? token.Register(() => call.Cancel()) : (IDisposable) null; + using (cancellationTokenRegistration) { - throw new InvalidOperationException("Cancellation of individual reads is not supported."); - } - var result = await call.ReadMessageAsync().ConfigureAwait(false); - this.current = result; + var result = await call.ReadMessageAsync().ConfigureAwait(false); + this.current = result; - if (result == null) - { - await call.StreamingResponseCallFinishedTask.ConfigureAwait(false); - return false; + if (result == null) + { + await call.StreamingResponseCallFinishedTask.ConfigureAwait(false); + return false; + } + return true; } - return true; } public void Dispose() diff --git a/src/csharp/Grpc.Core/Internal/ServerRequestStream.cs b/src/csharp/Grpc.Core/Internal/ServerRequestStream.cs index c65b960afb2..058dddb7ebb 100644 --- a/src/csharp/Grpc.Core/Internal/ServerRequestStream.cs +++ b/src/csharp/Grpc.Core/Internal/ServerRequestStream.cs @@ -49,13 +49,14 @@ namespace Grpc.Core.Internal public async Task MoveNext(CancellationToken token) { - if (token != CancellationToken.None) + + var cancellationTokenRegistration = token.CanBeCanceled ? token.Register(() => call.Cancel()) : (IDisposable) null; + using (cancellationTokenRegistration) { - throw new InvalidOperationException("Cancellation of individual reads is not supported."); + var result = await call.ReadMessageAsync().ConfigureAwait(false); + this.current = result; + return result != null; } - var result = await call.ReadMessageAsync().ConfigureAwait(false); - this.current = result; - return result != null; } public void Dispose()