Unity support

I know that Unity support isn’t planned for grpc-dotnet (#710 and #1155). However, since Grpc.Core is going to be deprecated (see The future of gRPC in C# belongs to grpc-dotnet), what is the plan for Unity users? I haven’t seen anything related in the blog post. I know that Unity support was experimental, but are you 100% dropping it?

[JamesNK]

Grpc.Net.Client on Unity requires Unity to add support for HTTP/2. If HTTP/2 and netstandard2.1 are supported, then Grpc.Net.Client will start working without any changes.

I want this to happen and I asked the Unity team about it here.

Basically, the work required is in Unity. You should tell them that gRPC is important to you so they prioritize it. I don’t know the best way to do that. Comment on Unity Future .NET Development Status?

[Blackclaws]

Alright, its actually even much simpler. You can use all the libraries targeting netstandard2.1 by default, the Grpc.Core.Api needs to be recompiled for netstandard2.1 instead of 2.0 else it won’t link in Unity (the System.Memory issue). You don’t even need to change any files that way.

If you’re using Google.Protobuf (which I guess a lot of you will be) you also need to recompile that for netstandard 2.1 (or include it in the project). You need to be careful there that it actually has a dependency set per target framework in the csproj:

  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
    <PackageReference Include="System.Memory" Version="4.5.3" />
    <!-- Needed for netcoreapp3.1 to work correctly. .NET is not able to load the assembly without this -->
    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.5.2" />
  </ItemGroup>

where you need to add:

  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.1' ">
    <PackageReference Include="System.Memory" Version="4.5.3" />
    <!-- Needed for netcoreapp3.1 to work correctly. .NET is not able to load the assembly without this -->
    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="6.0.0" />
  </ItemGroup>

do note the Version 6.0.0 for System.Runtime.CompilerServices.Unsafe as that is the version that Unity apparently ships with.

So in total you’re going to need the following dlls for Grpc Web to work in Unity:

• Grpc.Core.Api.dll (recompiled for netstandard 2.1)
• Grpc.Net.Client.dll (can be copied as a netstandard 2.1 version)
• Grpc.Net.Client.Web.dll (can be copied as well)
• Grpc.Net.Common.dll (same)
• System.Diagnostics.DiagnosticSource.dll (can be copied as is from the nuget package, I’ve used the netstandard 1.3 version)
• Microsoft.Extensions.Logging.Abstractions.dll (can also be copied from the nuget package, netstandard 2.0 package works fine here)

optionally:

• Google.Protobuf.dll (recompiled for netstandard 2.1)

You can then use any code generated clients in Unity. I have not tested server mode in any way and I don’t think there is an easy way to get it to work.

For code generated clients you can either add the source or just add any library that you built yourself targeting netstandard2.1.

Maybe in the future Grpc will work without the Web intermediate form, but for now Grpc Web is as good as its going to get and its still faster than REST.