HTTP/2: a response that was fully received is failed with HttpProtocolException (NO_ERROR) when the server sends GOAWAY and closes the connection while the request body is still open #136834

using System.Net;
using System.Net.Sockets;
using Grpc.Core;
using Grpc.Net.Client;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Server.Kestrel.Core;

// Usage: dotnet run -c Release -- <runs> [load]
var runs = args.Length > 0 ? int.Parse(args[0]) : 100;
var load = args.Length > 1 && args[1] == "load";
var bytes = Marshallers.Create<byte[]>(value => value, value => value);
var method = new Method<byte[], byte[]>(MethodType.DuplexStreaming, "repro.Service", "Connect", bytes, bytes);
var outcomes = new SortedDictionary<string, int>(StringComparer.Ordinal);
for (var run = 0; run < runs; run++)
{
	var port = FreePort();
	var started = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
	var end = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
	var builder = WebApplication.CreateEmptyBuilder(new WebApplicationOptions());
	builder.WebHost.UseKestrelCore().ConfigureKestrel(kestrel => kestrel.Listen(IPAddress.Loopback, port, listen => listen.Protocols = HttpProtocols.Http2));
	await using var app = builder.Build();
	// The server answers the duplex call with response headers, then ends it with trailers (grpc-status 14) without reading the request body.
	app.Run(async context =>
	{
		context.Response.ContentType = "application/grpc";
		await context.Response.Body.FlushAsync();
		started.TrySetResult();
		await end.Task;
		context.Response.AppendTrailer("grpc-status", "14");
		context.Response.AppendTrailer("grpc-message", "closed by the server");
	});
	await app.StartAsync();
	using var channel = GrpcChannel.ForAddress($"http://127.0.0.1:{port}");
	using var call = channel.CreateCallInvoker().AsyncDuplexStreamingCall(method, null, new CallOptions());
	await started.Task;
	// The client reads the response stream; its request stream stays open.
	var read = call.ResponseStream.MoveNext(CancellationToken.None);
	if (load)
		for (var item = 0; item < Environment.ProcessorCount * 4; item++)
			ThreadPool.UnsafeQueueUserWorkItem(_ => { var until = DateTime.UtcNow.AddMilliseconds(300); while (DateTime.UtcNow < until) { } }, null);
	// The server ends the call with its trailers and stops gracefully: GOAWAY(NO_ERROR), then it closes the TCP connection.
	end.SetResult();
	await app.StopAsync();
	string outcome;
	try
	{
		outcome = await read ? "message" : "end of stream";
	}
	catch (RpcException exception)
	{
		outcome = $"{exception.StatusCode}: {exception.Status.Detail}";
	}
	outcomes[outcome] = outcomes.GetValueOrDefault(outcome) + 1;
}
foreach (var (outcome, count) in outcomes) Console.WriteLine($"{count} of {runs}: {outcome}");

static int FreePort()
{
	using var listener = new TcpListener(IPAddress.Loopback, 0);
	listener.Start();
	return ((IPEndPoint)listener.LocalEndpoint).Port;
}