Function process_state 

pub fn process_state(record: &RunningRecord) -> ProcessState

Layers 1 and 2: the pid is alive, and the process holding it is the one that wrote the record.

Local and cheap, which is what makes this the candidacy test — a reader can apply it to every record without a single network round trip. The start time is read only for a live pid; see [classify] for how the two readings combine.