# Constants
5 -> X - dead (should never be seen).
process does not exist.
6 -> Z - Defunct ("zombie" / "obsolete") process, terminated but not reaped by its parent.
4 -> W - paging (not valid since the 2.6.xx kernel).
1 -> R - Running or runnable (on run queue).
3 -> T - Stopped, either by a job control signal or because it is being traced.
ProcessStateWaitingIO -.
2 -> S - Interruptible sleep (waiting for an event to complete).
0 -> D - Uninterruptible sleep (usually IO).
# Variables
ErrProcessDoesNotExist -.
# Type aliases
ProcessOutputReader -.
ProcessState -.
ProcessStoppedDelegate -.