LibuvConnection.OnRead throws Nullable object must have a value

[tmds]

To make the wrk tool generate large network requests, I set the number of pipelined requests to 2048. This causes an exception in LibuvConnection.OnRead which terminates the webserver.

"Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv": "2.0.0-preview2-24956"

To reproduce:

csproj

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>netcoreapp2.0</TargetFramework>
    <DebugType>portable</DebugType>
    <OutputType>Exe</OutputType>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="2.0.0-*" />
    <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv" Version="2.0.0-*" />
  </ItemGroup>
</Project>

Startup.cs

using System;
using System.Net;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;

namespace SampleApp
{
    public class Startup
    {
        public void Configure(IApplicationBuilder app)
        {
            app.Run(async context =>
            {
                var response = $"hello, world{Environment.NewLine}";
                context.Response.ContentLength = response.Length;
                context.Response.ContentType = "text/plain";
                await context.Response.WriteAsync(response);
            });
        }

        public static void Main(string[] args)
        {
            var hostBuilder = new WebHostBuilder()
                .UseKestrel(options =>
                {
     		    options.Listen(IPAddress.Parse("1.1.1.2"), 5000, listenOptions => {} );
                })
                .UseStartup<Startup>();
            hostBuilder = hostBuilder.UseLibuv(options => options.ThreadCount = 1);

            var host = hostBuilder.Build();
            host.Run();
        }
    }
}

NuGet.config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
    <add key="dotnet-core" value="https://dotnet.myget.org/F/dotnet-core/api/v3/index.json"  />
    <add key="dotnet-corefxlab" value="https://dotnet.myget.org/F/dotnet-corefxlab/" />    
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json"  />
    <add key="AspNetCore" value="https://dotnet.myget.org/F/aspnetcore-ci-dev/api/v3/index.json" />
  </packageSources>
</configuration>

wrk command:

wrk -H 'Host: server' -H 'User-Agent: Mozilla/5.0 (X11; Linux x86_64) Gecko/20130501 Firefox/30.0 AppleWebKit/600.00 Chrome/30.0.0000.0 Trident/10.0 Safari/600.00' -H 'Cookie: uid=12345678901234567890; __utma=1.1234567890.1234567890.1234567890.1234567890.12; wd=2560x1600' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' -H 'Accept-Language: en-US,en;q=0.5' -H 'Test:                                                                                           ' -H 'Connection: keep-alive' --latency -d 1 -c 256 --timeout 8 -t 32 http://1.1.1.2:5000/plaintext -s ~/pipeline.lua -- 2048

Exception thrown:

Unhandled Exception: System.InvalidOperationException: Nullable object must have a value.
   at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.LibuvConnection.OnRead(UvStreamHandle handle, Int32 status)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networking.UvStreamHandle.UvReadCb(IntPtr handle, Int32 status, uv_buf_t& buf)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networking.LibuvFunctions.NativeMethods.uv_run(UvLoopHandle handle, Int32 mode)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.Networking.LibuvFunctions.run(UvLoopHandle handle, Int32 mode)
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal.LibuvThread.ThreadStart(Object parameter)

dotnet info:

$ dotnet --info
.NET Command Line Tools (2.0.0-preview1-005972)

Product Information:
 Version:            2.0.0-preview1-005972
 Commit SHA-1 hash:  97da2a03b5

Runtime Environment:
 OS Name:     rhel
 OS Version:  7
 OS Platform: Linux
 RID:         rhel.7-x64
 Base Path:   /opt/dotnet/sdk/2.0.0-preview1-005972/

Microsoft .NET Core Shared Framework Host

  Version  : 2.0.0-preview1-002111-00
  Build    : 1ff021936263d492539399688f46fd3827169983

[halter73]

@tmds thanks for the report. I was able to reproduce.