A New Way to Asyncify (JSPI) is Entering Chrome Origin Trial

[Brendan Dahl]

I'm excited to announce that JavaScript Promise Integration (JSPI) is entering a Chrome origin trial in version 123. JSPI offers a new way to bridge synchronous C/C++ code with asynchronous JavaScript.

Highlights:

• Code Size Reduction: JSPI promises significantly smaller Wasm output sizes compared to asyncify.
• Performance: In most cases JSPI should be faster, but there might be scenarios where issues arise (see the V8 blog for details).

Call to Action: If you're using ASYCNIFY=1 or need to interact with async JS, we encourage you to try out JSPI during the origin trial and provide feedback. To enable JSPI in Emscripten use the setting -sASYNCIFY=2 and refer to the asyncify docs for more information.

Let us know if you run into issues!

[Александр Гурьянов]

Hi, great to know that JSPI is moving forward, I tested it on couple of my projects.

1. Dune 2

compiles: ✅ (yes)

regular build: 428Kb

jspi build: 336 Kb -22%

works in chrome: ✅ (yes)

performance: same (old version also was blazing fast)

2. js-dos dosbox

compiles: ✅ (yes)

regular build: 1.4Mb

jspi build: 1.4 Mb

works in chrome: ❌ (no), freezes tab on start

3. js-dos dosbox-x (with exceptions!)

compiles: ✅ (yes)

regular build: 6.3Mb

jspi build: 5.9 Mb -7%

works in chrome: ❌ (no), freezes tab on start

2/3 how-to reproduce:

You can find in jspi version of js-dos here: https://v8.js-dos.com/tmp/jspi.zip.

1. Extract it

2. Change origin meta tag in test/dhry2.html and test/test.html

3. Serve contents of dist folder and open test/dhry2.html or test/test.html in chrome

dhry2.html - is a benchmark, it will print performance estimation if works

test.html - is a js-dos testsuite, all tests should pass (press "Start Tests" button to start).

Both pages stuck at the beginning, regular version works just fine.

--

Best regards, Alex

сб, 16 мар. 2024 г. в 00:16, 'Brendan Dahl' via emscripten-discuss <emscripte...@googlegroups.com>:

--
You received this message because you are subscribed to the Google Groups "emscripten-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email to emscripten-disc...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/emscripten-discuss/3e6cfe84-11db-4235-b548-edee7c68cf40n%40googlegroups.com.