spec clarification: allow multiple open() and close() requests, and multiple calls to requestMIDIAccess()

[toyoshim]

For now the spec say nothing about multiple outstanding open() or close() requests.
But, what happens if open() is called before the previous open() is not resolved?

I feel it's ok to call async function that returns Promise many times before the previous call finishes.
Before JavaScript has the Promise, typical async APIs, e.g., File API, does not allow multiple requests, and the second request will throw InvalidStateError. But we can manage multiple requests with Promise.

[cwilso]

This should also apply to multiple requestMIDIAccess calls - where the app may decide to time out and re-request without sysex, for example.

[toyoshim]

Agreed. Current Chrome implementation also allows multiple requestMIDIAccess calls.

[agoode]

A question about Promises. Would the spec allow implementations to return the same Promise object for multiple open() calls?

[cwilso]

I think you actually want to have different promises.