.Net Core Blimey! (16/07/2015)
- 2. This is Matt Ellis He works for Microsoft, and is a developer on the .NET Core team. This is not me.
- 3. This is Matt Ellis He works for JetBrains, and is an interested amateur in .NET Core. This is me.
- 4. What is .NET Core? New .NET stack - CLR + BCL Open Source Cross platform (eventually) Standalone - per-application installs Factored for modularity - “cloud optimised” Everything ships as NuGet packages, including the runtime Not finished…
- 5. .NET Core != .NET Framework NOT a new version of the .NET Framework • .NET Framework is going nowhere • .NET Core is 5.0 .NET Framework is 4.6 • .NET Core is a fork of the .NET Framework Code merged back to TFS • .NET Core is (currently) a strict subset of the .NET Framework • Missing pieces in .NET Core Windows: WinForms, WPF, COM, etc. Platform: AppDomains, Remoting, Reflection.Emit, etc. • Different constraints: Ship cycles, compatibility, system wide install
- 6. Why? Multiple .NET stacks. Incompatibilities Portable Class Libraries not scalable Cross platform Independent release cycles Runtime, BCL, apps Nano Server Tidy up 15 years of evolution
- 7. History Started with .NET Framework 2.0
- 8. How do I get it? DNX - Dot Net Execution Environment Maintained by asp.net team Stable builds on nuget.org Unstable on myget.org .NET Core team maintain own build dnvm install latest -r coreclr -u
- 9. Build from source! How do I get it?
- 11. .NET Native Alternative runtime • AOT compilation • Compiles all dependencies Tree shaking • Reflection? Via xml! • Windows Store apps only • Closed source • On hold • LLILC - LLVM based JIT/AOT (OSS)
- 12. CoreCLR The new runtime.
- 13. dotnet/coreclr JIT compiler (RyuJIT), Garbage Collector, Platform Abstraction Layer - C++ mscorlib (tightly coupled to runtime) - C# PAL - OS and platform differences. E.g. exception handling, threads, etc. P/Invoke to OS, FEATURE #ifdefs Book of the Runtime! Mirror back to TFS
- 14. CoreFX The new BCL.
- 15. dotnet/corefx Factored for modularity - each solution/assembly is a package Some platform specific implementations, e.g. System.Console, Process.Interop.Unix.cs, etc. Might throw PlatformNotSupportedException (e.g. Console.get_ForegroundColor ) Build is based on project.json, packages as references Mirrored to TFS + .NET Framework High compatibility bar for changes, transparent API review process Console.get_ForeoundColor PlatformNotSupportedException
- 16. AppModels Or: How do you run a .exe on Unix?
- 17. How the application is hosted and run Environmental services What is an AppModel? Bootstrap the CLR Execute the application
- 18. .NET Framework AppModels .NET .exe Originally a native stub that loaded the CLR (x86 only!) Special cased by OS loader since Windows XP Loads mscoree.dll, which initialises CLR and executes app IIS/asp.net Pre-IIS 7 - ISAPI filter IIS 7 directly integrates CLR Pipes requests/responses to managed code Lifetime management Windows Phone / Windows Store Magic! “Application host” loads CLR Integrates with environment events. E.g. suspend and resume applications Pre-compiled / .NET Native
- 19. corerun DNX - .NET Execution Environment (asp.net) Windows 10 UWP Applications .NET Core AppModels coreconsole / osxcorebundlerun
- 20. DNX Dot NET Execution Environment asp.net 5 Targets .NET Core / .NET Framework / Mono In memory compilation via Roslyn Changes project system Reference packages, not assemblies More…
- 21. • Packages for runtime and BCL • BCL factored into many packages • NuGet at heart of project system (DNX) • NuGet is the new Portable Class Library • Changing daily. Undocumented… NuGet Bleeding edge.
- 22. How does this affect us? Let NuGet be NuGet Don’t target a framework Add NuGet dependencies for all BCL assemblies Specify required versions of BCL assemblies Let NuGet sort it out Effectively, there is no longer a fixed framework version to target
- 23. New Target Framework Monikers Brand new • dotnet - - .NET Core contracts. Use this! • dnx451 , dnx46 - DNX targeting .NET Framework 4.5.1, 4.6 • dnxcore50 - DNX targeting .NET Core • netcore50 - .NET Core 5.0 on Windows (UWP apps. Follows netcore45 / win8 , netcore451 / win81) dotnet dnx451 dnx46 dnxcore50 netcore50 netcore45 win8 netcore451 win81
- 24. What About Compatibility? All .NET Core packages are PCLs. Kinda.
- 25. PCL Refresher 1. A PCL is a class library that needs to run on multiple platforms and versions (e.g. .NET Framework, Windows Phone, Xamarin) 2. It defines a common subset of APIs that are available on ALL of the required versions of these platforms - a “Profile” 3. When targeting a Profile, the compiler references a set of Reference Assemblies These describe the API with empty types, and forward types to correct assemblies 4. At runtime, the real assemblies on the target platform implement the APIs Can also forward types to other assemblies
- 26. Portable Class Libraries • PCL hides platform specific implementation details behind a common API contract • Profiles do not scale. The more versions and platforms, the more Profiles…
- 27. Why is this important? Isn’t .NET Core a common, compatible, cross platform implementation? • The BCL is the Base Class Library. It’s low level, and has to worry about underlying platform differences, e.g. file IO • The BCL needs to be abstracted away from the platform, to allow for platform specific implementations. And refactoring!
- 28. Reference Assemblies BCL packages include a Reference Assembly in ref • This is referenced at compile time and provides the contract for the API, just like PCL Reference Assemblies • The runtime implementation (e.g. libnetcore50 ) handles platform/host specifics ref libdnxcore50
- 29. Why is this important? This is how compatibility works • Reference Assemblies allow consuming .NET Core packages from .NET Framework and other PCL platforms • Reference Assembly provides the contract, forwards any types • Implementation assemblies provide potential platform specific implementations
- 30. Compatibility (not a guarantee) • .NET Framework 4.6 can consume .NET Core packages • .NET Core 5.0 is a subset of .NET Framework 4.6 Should be able to consume .NET Framework 4.6 packages • .NET Core can consume PCL libs that are compatible with System.Runtime.dll (facade that forwards to e.g. mscorlib.dll) • A new PCL Profile will include .NET Core (e.g. )portable-dotnet+…+…
- 31. Known Unknowns • How are OS specific implementations going to be shipped? • Do we need a Reference Assembly for each package? • What are the compatibility fallbacks? E.g. net46 → net45 → net40. • Why do we need platform/host TFMs (e.g. dnxcore50 ) when we can specify dependencies? dnxcore50 net46 net45 net40
- 32. What does this mean for Mono? Lots. Or not much. Mono == .NET Framework Mono already cross platform Mono’s focus is non-Windows mobile (Xamarin) .NET Core’s focus is server and Windows UWP Mono can include CoreCLR + CoreFX code
- 33. Where does Roslyn fit in? Orthogonal. Runs on .NET Framework + Mono Planned for .NET Core Compiling CoreCLR + CoreFX currently requires Windows C# compiler written in C#
- 34. .NET Core Cross platform Open Source NuGet everywhere Bleeding edge Icons: http://icons8.com/ The future of .NET
- 35. Links CoreCLR - https://www.github.com/dotnet/coreclr CoreFX - https://www.github.com/dotnet/corefx DNX - https://github.com/aspnet/Home @citizenmatt