Struct TaskHandle 

pub struct TaskHandle { /* private fields */ }

Coordination state for one task. Embedded inside TaskNode.

Every node is single-instance, so the state is one word of per-node flags plus single-consumer signals — no counts, no fan-out. Written by one side (task or supervisor) and read by the other: the supervisor requests exit (SHUTDOWN + shutdown_wake), the task acks it (DROPPED + dropped_wake), a parked Pause-mode task resumes on resume_wake, and the scaling policy reads RUNNING/BUSY. See the private flag module for each bit.