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Yes, currently input goes into a propmpt() and it doesn't output anything unless you hit "Cancel" on the prompt, definitely a bad time. Python allows you to re

Yes, currently input goes into a propmpt() and it doesn't output anything unless you hit "Cancel" on the prompt, definitely a bad time. Python allows you to reach in and replace the core interpreter loop, so this may be an avenue to have our own asyncify-like function pop out to JS land and restore state correctly (which we can be smart about since we are the interpreter). It may also be possible to write something that runs Python in a webworker and communicate with it over a sharedarraybuffer, but that I'm a bit more hazy on. Pyodide has some discussion of this in https://github.com/pyodide/pyodide/issues/1219 https://github.com/pyodide/pyodide/issues/1219 and https://github.com/pyodide/pyodide/issues/1503 https://github.com/pyodide/pyodide/issues/1503. This is definitely the hardest part of getting Python to work. Well, hardest after the hardest part of building a compiler toolchain like Emscripten :)

benno128 5y ago
In WebAssembly.sh (https://github.com/wasmerio/webassembly.sh https://github.com/wasmerio/webassembly.sh) they run WASM binaries in a Web Worker and then use `SharedArrayBuffer` to block the WebWorker while the main thread does some work (e.g. collect input). You could use a similar solution. When building Runno (https://runno.dev https://runno.dev) I forked off that project and did a bunch of other things on top to get blocking to work in Safari and non-cross-origin-isolated contexts. Ultimately I think it's JavaScript's (or whichever host language) responsibility to block when the binary calls out (if that is the expected semantics).
- deleted 5y ago
  [deleted]
- est31 5y ago
  Does the SharedArrayBuffer approach offer any way to tell the OS scheduler to wait? Because the only waiting method I know of is busy waiting, aka wasting cycles at 100% of a CPU core. In normal processes you can call a sleep function, which saves CPU cycles, but there is no synchronous method for that available in javascript.
  - benno128 5y ago
    It's part of the Atomics feature set (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/wait https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...). You have a shared chunk of memory and you say "please sleep until this memory changes". Then it's up to the host to change that memory.
    - est31 5y ago
      Oh that's pretty neat, didn't know about that.

benno128 5y ago

In WebAssembly.sh (https://github.com/wasmerio/webassembly.sh https://github.com/wasmerio/webassembly.sh) they run WASM binaries in a Web Worker and then use `SharedArrayBuffer` to block the WebWorker while the main thread does some work (e.g. collect input). You could use a similar solution. When building Runno (https://runno.dev https://runno.dev) I forked off that project and did a bunch of other things on top to get blocking to work in Safari and non-cross-origin-isolated contexts. Ultimately I think it's JavaScript's (or whichever host language) responsibility to block when the binary calls out (if that is the expected semantics).

deleted 5y ago
[deleted]
est31 5y ago
Does the SharedArrayBuffer approach offer any way to tell the OS scheduler to wait? Because the only waiting method I know of is busy waiting, aka wasting cycles at 100% of a CPU core. In normal processes you can call a sleep function, which saves CPU cycles, but there is no synchronous method for that available in javascript.
- benno128 5y ago
  It's part of the Atomics feature set (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/wait https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...). You have a shared chunk of memory and you say "please sleep until this memory changes". Then it's up to the host to change that memory.
  - est31 5y ago
    Oh that's pretty neat, didn't know about that.