Struct Pause 

pub struct Pause(/* private fields */);

A request to park the run at its next node boundary.

Cloning is how the request travels: the loop keeps one handle and hands a clone to each Runner, and every clone points at the same flag. There is no channel because there is nothing to send - the only message is “park”, it is idempotent, and a flag cannot be missed by a receiver that was not listening yet.

The boundary is what makes this cheap. Every node writes the run’s state before the next one starts, and every node skips what is already recorded: prep returns early once candidates exist, implement asks only the seats with nothing on disk, judge returns early once judgements exist. So a parked run resumes into exactly the node it stopped before, and no agent work is thrown away. Killing the process mid-node, by contrast, loses whatever the seats in flight had not yet written - which for an implement wave is an hour of paid work.

A Runner watches two independent handles of this type - see Runner::on_pause and Runner::watch_interrupt - never one shared between them. magi serve’s own shutdown (Stop::park) hands out one clone covering the whole daemon’s lifetime and is never asked to un-park, which is correct exactly because nothing is dispatched after it fires. magi serve’s interrupt scheduler needs the opposite lifetime - a run that parks for an interrupted task must go on to run other tasks afterward - so it mints a fresh, unshared Pause per run instead of reusing the daemon-wide one.

Implementations

impl Pause

pub fn new() -> Self

A pause nobody has asked for yet.

pub fn park(&self)

Ask the run to park at its next node boundary. Idempotent.

pub fn park_because(&self, reason: impl Into<String>)

Same as Pause::park, but records why, for Runner::park_here to fold into the run’s own park event - so an operator reading the run later knows this was a deliberate interrupt rather than a shutdown or a binary swap. The first reason recorded wins; a park already in flight is not relabelled by a second, unrelated request.

pub fn parked(&self) -> bool

Has a park been asked for?

pub fn reason(&self) -> Option<String>

Why the park was asked for, when the caller used Pause::park_because.

Trait Implementations

impl Clone for Pause

fn clone(&self) -> Pause

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Pause

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Pause

fn default() -> Pause

Returns the “default value” for a type.