Konubinix' opinionated web of thoughts

WebAssembly

fleeting

https://hacks.mozilla.org/2017/02/creating-and-working-with-webassembly-modules/

web platform can be thought of as having two parts:

  • A virtual machine (VM) that runs the Web app’s code, e.g. the JavaScript code that powers your apps.
  • A set of Web APIs that the Web app can call to control web browser/device functionality and make things happen (DOM, CSSOM, WebGL, IndexedDB, Web Audio API, etc.).

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

Historically, the VM has been able to load only JavaScript.

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

WebAssembly is a different language from JavaScript, but it is not intended as a replacement. Instead, it is designed to complement and work alongside JavaScript,

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

JavaScript is a high-level language, flexible and expressive enough to write web applications.

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

WebAssembly is a low-level assembly-like language with a compact binary format that runs with near-native performance and provides languages with low-level memory models

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

virtual machine that we talked about earlier will now load and run two types of code — JavaScript AND WebAssembly.

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

different code types can call each other as required

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

WebAssembly cannot currently directly access the DOM; it can only call JavaScript,

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

to access any Web API, WebAssembly needs to call out to JavaScript, which then makes the Web API call.

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

Emscripten therefore creates the HTML and JavaScript glue code needed to achieve this.

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

Emscripten implements popular C/C++ libraries like SDL, OpenGL, OpenAL, and parts of POSIX. These libraries are implemented in terms of Web APIs and thus each one requires some JavaScript glue code to connect WebAssembly to the underlying Web API.

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

part of the glue code is implementing the functionality of each respective library used by the C/C++ code

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

glue code also contains the logic for calling the above-mentioned WebAssembly JavaScript APIs to fetch, load and run the .wasm file.

https://developer.mozilla.org/en-US/docs/WebAssembly/Concepts

WebAssembly System Interface

WebAssembly beyond the browser, because it provides a fast, scalable, secure way to run the same code across all machines

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

WebAssembly needs a system interface for a conceptual operating system

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

This is what WASI is — a system interface for the WebAssembly platform.

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

need a way to control which programs and users can access which resources.

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

When a program needs to ask the kernel to do one of these things, it asks using a system call

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

only way that your code can access the system’s resources — through system calls

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

operating system makes the system calls available.

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

each operating system has its own system calls

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

Most languages provide a standard library. While coding, the programmer doesn’t need to know what system they are targeting. They just use the interface

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

system interface comes in. For example, printf being compiled for a Windows machine could use the Windows API to interact with the machine. If it’s being compiled for Mac or Linux, it will use POSIX instead

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

WebAssembly needs a system interface for a conceptual operating system, not a real operating system

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

Emscripten created its own implementation of libc. This implementation was split in two — part was compiled into the WebAssembly module, and the other part was implemented in JS glue code. This JS glue would then call into the browser, which would then talk to the OS.

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

when people started wanting to run WebAssembly without a browser, they started by making Emscripten-compiled code run. So these runtimes needed to create their own implementations for all of these functions that were in the JS glue code.

https://hacks.mozilla.org/2019/03/standardizing-wasi-a-webassembly-system-interface/

WASM+WASI existed in 2008, we wouldn’t have needed to create Docker. That’s how important it is. WebAssembly on the server is the future of computing.

https://wasmlabs.dev/articles/docker-without-containers/

WebAssembly as the ‘successor’ to containers and the next logical step in infrastructure deployment

https://wasmlabs.dev/articles/docker-without-containers/

WebAssembly is as an alternative ‘backend’ for Docker tooling. You can use the same command line tools and workflows, but instead of using Linux containers, it is implemented using WebAssembly-based container equivalents.

https://wasmlabs.dev/articles/docker-without-containers/

runtimes

wasmer

wasmtime

pronunciation

WebAssembly (abbreviated WASM, pronounced waz-um)

https://matt-rickard.com/what-is-webassembly

(Wasm should be pronounced like awesome starting with a W ).

https://github.com/petersalomonsen/wasm-git

WebAssembly, when you read Wasm. Is it wah-sum, w-a-s-m, or do you just read ‘web assembly’?

wah-sum

https://users.rust-lang.org/t/pronunciation-of-things-from-rust/54744?page=2

we expect that developers are going to use both WebAssembly and JavaScript in the same application

https://hacks.mozilla.org/2017/02/creating-and-working-with-webassembly-modules/

WebAssembly is a little bit different than other kinds of assembly. It’s a machine language for a conceptual machine, not an actual, physical machine.

https://hacks.mozilla.org/2017/02/creating-and-working-with-webassembly-modules/

another tool called Emscripten which is a bit easier to use at the moment. It has its own back-end that can produce WebAssembly by compiling to another target (called asm.js) and then converting that to WebAssembly. It uses LLVM under the hood, though, so you can switch between the two back-ends from Emscripten.

https://hacks.mozilla.org/2017/02/creating-and-working-with-webassembly-modules/

Notes pointant ici