1180980 - Consider adding a parent count to SavedFrame objects for internal use

Status: NEW

(Core :: JavaScript Engine, defect)

Description

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

This would allow js::SavedStacks::adoptAsyncStack to return early and avoid two O(n) traversals when the async stack is in the right compartment and the number of parents is less than our maximum.

Comment 1

[:Paolo Amadini]

(In reply to Nick Fitzgerald [:fitzgen][:nf] from comment #0)
> This would allow js::SavedStacks::adoptAsyncStack to return early and avoid
> two O(n) traversals when the async stack is in the right compartment and the
> number of parents is less than our maximum.

This is nice but wouldn't help much with the case we're optimizing for, that is the iterative async calls, where the parent count exceeds the maximum allowed frames and we need to get close to the root anyways to recreate the stack. So I'm not sure whether by itself it can justify the memory and complexity overhead.