Plan for enabling high-resolution timers

[annevk]

In tc39/ecma262#1435 I detailed an approach the HTML community is planning on taking for reenabling ECMAScript's SharedArrayBuffer. This also affects Wasm if Wasm ever gets its own thread primitive (rather than building on top of workers and postMessage()) or some other high-resolution timer mechanism. Your input is most welcome.

cc @arturjanc @cdumez @csreis @linclark @lukewagner @mystor @rniwa

[littledan]

For Wasm threads, see https://github.com/WebAssembly/threads , cc @binji. Should this issue be filed there? Maybe the threads Web API should tie into this plan.

[annevk]

To be clear, that is the plan. It should fall out automatically given eventual HTML integration is as I understand it, since postMessage() is the underlying primitive for Wasm too.

I filed WebAssembly/threads#124 to spread this message there too.

(If Wasm eventually gets "actual" threads those would only be allowed if this new agent cluster flag is set, but it seems those are still far away.)

[annevk]

In web-platform-tests/wpt#17690 I'm looking at updating tests to account for this new design. I don't think it affects any existing wasm/ tests as the once I encountered specify jsshell as the global, which isn't a standardized thing per se.

[annevk]

The HTML Standard now fully defines this. Firefox 79 implements it (shipping later this month). Chrome will migrate to it. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer/Planned_changes is still a useful high-level summary.

Feel free to close this.