A FIFO of blocking jobs, run one at a time on a background thread that a
post starts when none is running and that exits once the queue is empty.
Each job returns a completion, and completions run only in pump(), on
the owner's thread. Unlike RPCWorker and AsyncTaskManager nothing ever
joins: abandon() (also run by the destructor) drops queued jobs and
undelivered completions and refuses later posts, and a job stuck in a
blocking call finishes on its own thread. It is meant for backend calls
that can wait out a long scan and may have to be given up. post()
reports a dropped job (abandoned lane, or no thread could be started),
and waitIdle() is bounded.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
DanSandClaude Opus 5.5
b2a57a61a0