Change 'incompletely specified behavior' phrasing to 'limited local nondeterminism'

[lukewagner]

As discussed in #107.

[kripken]

apologies for an unimportant question, but was the space before : intentional here? (it would feel natural for me to not have it there, but maybe it's a style I'm not familiar with)

[lukewagner]

You're right, it'd look better w/o space before.

[kripken]

Another probably unimportant note, it might be better to avoid saying "fully deterministic" because in a more general sense, there is or will be nondeterminism in wasm - stuff like calling a random number generator. Very nitpicky of course, as your intention is clear, so feel free to ignore.

[lukewagner]

Haha, good point, I forgot about random. I can reword.

[sunfishcode]

lgtm

[jfbastien]

Drop "near-"? We want native performance!

[sunfishcode]

I think "near-" is an acknowledgement that we are sandboxed and that we are providing a portability abstraction that discards certain unappetizing-but-nonetheless-expedient implementation details, and until we get hardware support there's always going to be some overhead. But ultimately it's a question of taste here.

[lukewagner]

Yeah, this is just the conservative "don't overpromise" engineer in me, but "native" is probably fine here, so I'll take out "near-".

[jfbastien]

Missing period.

[jfbastien]

lgtm after nit, and assuming you move the race/data stuff to another PR.

[lukewagner]

Pulling this now-hidden note into the main discussion:

So as @jfbastien pointed out, there are two levels of non-determinism here:

1. the non-seq-cst you get if you have a data race
2. even with seq-cst, it's still non-deterministic

and 2 isn't really called out, so I think a further update is necessary.

[lukewagner]

How about this?

[jfbastien]

lgtm

[lukewagner]

@sunfishcode too?

[sunfishcode]

I don't know if this is too pedantic, but it's also visible between API calls and WebAssembly program termination.

[lukewagner]

True true, we must never forget termination.

[sunfishcode]

@sunfishcode has an outstanding concern.