If that binary is supposed to have its own event loop, how do I achieve that? Seems like I'd have to hook back into the JS event loop, at which point my poor binary becomes subject to all the DOM blockers I was trying to avoid in the first place... :(
What is really needed is the ability to preempt/resume javascript in workers.
You could fudge that with a preprocessor script that inserted, at judicious points, polling of a pseudo-interrupt flag. You'd have to use a SharedArrayBuffer which you can't have because it got disabled post-spectre.
Unfortunately, I fear any mechanism that works properly would let you do things precisely and well and would consequently be blocked as a possible avenue for spectre.
The current native app (say, in Linux) has both a scripting language and a DSP "dataflowy" language that can run and interact in the same process. This means the user can manually (or programmatically) turn on DSP processing opportunistically. However, with the Web Audio idea above this means that the software I'm porting must be calculating its DSP graph from the AudioWorklet callback at all times for the software to work at all. If I suspend audio computation in the parent script time would no longer move forward. Or I'd have to switch to having the DOM poll the worker-- feeding it the current time-- which I'm just guessing would kill performance.