[Development] Qt for WebAssembly

[Edward Welbourne]

Morten Sørvig (14 March 2018 10:54)
> (The alternative would be to wait it out - perhaps threading support will be
> enabled and stable in all browsers before we get to merge wip/webassembly).

>From recent discussion with a Firefox developer, I gather that browser
vendors are generally trying to restore SharedArrayBuffer in wasm, at
least; which is likely to result in it also being restored to JS.

However, mitigating the Spectre weakness may involve constraining the
use of SharedArrayBuffer; details remain unclear (and shall probably
require developers from different browsers to reach a consensus on
what's a good way to do this).

He also noted that SharedArrayBuffer is a run-time preference in Firefox
(about:config -> javascript.options.shared_memory); but it's a global
option, not per-site, so enabling it may make expose you to Spectre
exploits.

	Eddy.