WebAssembly: Bytecode for the web

Eine C++-Anwendung im Web, integriert in einer Single Page Application (SPA) – das geht? Ja, mit WebAssembly (WASM). Nativer Code im Web hat sinnvolle Anwendungszwecke für die unterschiedlichsten Szenarien. Durch die Möglichkeit, existierenden C++-Code speziell kompiliert in den Webbrowser zu laden, können komplexe Algorithmen und Berechnungen – wie sie etwa in der Bild- und Videoverarbeitung vorkommen – Cross-Plattform auf nahezu allen Endgeräten ausgeführt werden. In diesem Vortrag zeigt Ihnen Martina Kraus zunächst die Grundlagen von WebAssembly anhand eines kleinen C++-Hello-World-Beispiels. Im Anschluss widmet sie sich dann der Frage, wie man eine existierende C++-Anwendung in eine Angular-basierte SPA integrieren kann, um das Beste aus beiden Welten zu nutzen. Dabei sollen typische Designpatterns und evtl. notwendige Umbauarbeiten an bestehendem Code ebenso beleuchtet werden wie die WASM Toolchain, mit der man zum Ziel einer nativ-angereicherten modernen Web-App kommt.

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1. WebAssembly: Native Bytecode for the web C++ goes Web Martina Kraus @MartinaKraus11 Software Developer
2. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io @MartinaKraus11 me@martina-kraus.io martina-kraus.io Martina Kraus • Software Developer • Focus: • Web applications with Angular • WebAssembly
3. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io • WebAssembly: Native Bytecode for the Web • Emscripten and LLVM • C++ goes Web • Porting C++ into a running Angular application • Porting Guidelines • The Future of WebAssembly Agenda
4. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io WebAssembly Native Bytecode for the Web
5. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io WebAssembly?
6. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Why should I care about the Web? • The Browser as an application platform • Browser APIs (USB, Service Workers ...) and HTML5 evolving rapidly • Runs on almost every platform
7. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io The Challenge • Customers writing applications in C / C++ https://www.tiobe.com/tiobe-index/
8. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io • Low-Level Bytecode for the Web • V1 shipped as Minimum Viable Product • Fast, efficient, portable • Uses existing sandboxing tools • Standard and specification through W3C WebAssembly (wasm)
9. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io • No plug-ins needs to be installed (Native technology) • Implemented in all major browsers (2017+) High level design goals • Idea: Bring all programming languages to the browser • Targeted languages such as C, C++ or Rust (= languages without garbage collection) • Defining a portable size- and load-time efficient binary format
10. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io • Re-use existing code, embedded in larger JavaScript / HTML application WebAssembly and JavaScript • Main application & logic in WebAssembly, UI in JavaScript / HTML / CSS • Entire code base in WebAssembly • With a tiny bit JavaScript for fetching • Only recommended for 3D rendering
11. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Can I use
12. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io • Inside the web browser: • Rich-Media improvements (editing video, image recognition, music streaming) • Scientific visualization and simulation • Encryption And what are the real-life Use-Cases? • Outside the web browser: • Server-side compute of untrusted Code / Server-side application • Hybrid native apps on mobile devices
13. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Emscripten and LLVM: The C++ Toolchain for WebAssembly
14. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io C++ to WASM • C / C++ tools & compilers • Emscripten: LLVM-to-JavaScript-or-WASM compiler • LLVM: The modern C / C++ compiler toolchain
15. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Emscripten • Cross compiles C++ with LLVM to bytecode and then to WASM • Support standard C++-Libs (Import via build step) • SDL, EGL, GLUT, … • Maps OpenGL to WebGL for 3D rendering • Extends LLVM optimizations with JavaScript optimizations
16. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Toolchain Clang / LLVM (Fastcomp) Emscripten Compiler Frontend (emcc) Emscripten SDK Manager (emsdk) .cpp .c .js .html .wasm Ports (WebGL) Build pipeline Emscripten-Tools Input / Output-Files
17. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io DEMO The C++ Toolchain for WebAssembly
18. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Furthermore with CMake / Makefiles • Makefiles are the C++ equivalent for MSBuild (.NET) Defining Makefile in CMakeLists.txt: • Configuration and compilation: if (${CMAKE_SYSTEM_NAME} MATCHES "Emscripten") set_target_properties(app PROPERTIES LINK_FLAGS "-o app.js") endif () C:\emscriptenDemo> emconfigure cmake . C:\emscriptenDemo> emmake make
19. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io DEMO Calling a C function with JavaScript
20. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io DEMO Integration of an C++ application inside a Single Page Application (Angular)
21. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io WebAssembly C++ Porting Guidelines
22. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io • Input support via GLFW / Multimedia support via SDL Good help from Emscripten ports • Own Emscripten-Library (emscripten.h) • OpenGL is provided different modes: • WebGL-friendly subset of OpenGL ES 2.0 / 3.0 (default) • https://github.com/emscripten-core/emscripten/tree/master/tests/glbook • OpenGL ES 2.0 / 3.0 emulation (features that can‘t be mapped to WebGL)
23. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io • Compiler Flags: • Browser used SharedArrayBuffer for Memory and WebWorkers for Threading Migration: Multithreading (not supported yet) -s USE_PTHREADS = 1 -s PTHREAD_POOL_SIZE = <int> • BUT: January 2018 Browsers disabled SharedArrayBuffer • High vulnerability issues • There is an option to set a flag-option inside your browser (at your own risk)
24. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Migration: What is not supported / needs to be rewritten • Native Code: • Inline Assembly (Code that is scanning / manipulating registers or the stack) • Developing both options – portable and native • Detecting emscripten in preprocessor __EMSCRIPTEN__
25. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io The Future of WebAssembly After v1 (the MVP), the consortium keeps working on new features • Garbage Collection • Direct DOM access • Multi-Threading • Many more …. • https://github.com/WebAssembly/design/blob/master/FutureFeatures. md
26. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Summary • WebAssembly ships C++ to the web • Cross-compiled WebAssembly runs inside every modern web browser • And actually really fast: https://github.com/guybedford/wasm-demo
27. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Samples for CMake and Angular Integration: https://github.com/martinakraus/BastaSpring2019Samples
28. WebAssembly: Native Bytecode for the Web C++ goes Web @MartinaKraus11 me@martina-kraus.io Links • Emscripten: https://emscripten.org/ • WebAssembly: https://developer.mozilla.org/en-US/docs/WebAssembly • LLVM: https://llvm.org/ • Doom 3 Demo: http://www.continuation-labs.com/projects/d3wasm/
29. @MartinaKraus11 me@martina-kraus.io WebAssembly: Native Bytecode for the Web C++ goes Web Thank you For your kind attention! Slides: https://speakerdeck.com/martinakraus/webassembly-bytecode-for-the-web