Handles whose wait() we EXPLICITLY awaited and saw fulfilled.
Best-effort count — a child that completes inside another's
wait() may finish (and unregister) before we get a chance to
await it directly. The DRAIN is still guaranteed (registry empty
on return); only the COUNT is approximate.
Readonlyfailed
failed:number
Handles whose wait() rejected. Same best-effort semantics.
Readonlypending
pending:number
Handles still in-flight when the deadline expired. 0 indicates
a successful (complete) drain — registry was empty on return.
Handles whose
wait()we EXPLICITLY awaited and saw fulfilled. Best-effort count — a child that completes inside another'swait()may finish (and unregister) before we get a chance to await it directly. The DRAIN is still guaranteed (registry empty on return); only the COUNT is approximate.