tracking of promise rejections

[Uzlopak]

see nodejs/node#52108

[RafaelGSS]

Can you elaborate more the performance bottleneck and suggested solution? @Uzlopak

[Uzlopak]

@RafaelGSS

IIRC my PR solved the issue.

The Problem was that we tracked the Promises in an Array or so, to keep a strong reference and avoid the Promises being accidentlx garbage collected. But the processing of the Array was really imperformant. On every iteration of the event loop it goes over the array and processed them. If there was new promises, they got added to the Array and it again started to process the whole Array and then check if new promises got added... So the Array got bigger and bigger and bigger and we never got to the next event loop iteration

IIRC my PR basically changed it to only process the newly added promises, and that improved the overall performance and avoided the issue of never getting to the next event loop iteration.

[RafaelGSS]

Thanks!