Module waiter 

The waiter: something that keeps waiting on a question after the process that asked it is gone.

magi ask blocks in the agent’s own shell tool, and that tool kills a wait that runs long (see ask::WAIT_SLICE). An agent can also background the call and simply finish. Either way the question outlives the only process that would have read the owner’s answer, and the owner’s reply lands in a file nobody is polling - the phone then says “waiting for the agent” while there is no agent to wait for.

This module is the guarantee that something is always on the other end. It runs inside magi serve, on its own cadence rather than the queue’s, and for every question a magi ask filed it decides one of three things:

• the asker is still there (its Lease is fresh): do nothing. A second agent must never be started while the first is blocked;
• the asker is gone and the owner has said or answered something the agent has not read: resume the same seat’s CLI session with the question, the thread so far and the owner’s words, so the agent that holds the context carries on;
• nobody answered before answer_timeout: abandon it, in the same words the asker would have used.

Shape

Same split as crate::queue and crate::ask: decide is pure - a question, a lease, a clock and a bool in, an Action out - and every filesystem or process effect is in Waiter::tick. State lives on disk (the question record and its lease), so a restarted daemon picks up exactly where the last one stopped, including an answer nobody has read yet.

What it will not do

It never starts a fresh consultant. If the seat’s session cannot be resumed (agent::has_session says no, the working directory is gone, the run is over, the agent left the roster) the question stays as it is, the owner gets a notification saying why, and nothing else runs. A new agent would have to be caught up on everything the first one knew, and would act on the owner’s words without the context they were written against.

It never assumes a resume worked either: a turn that fails or times out leaves the word undelivered, and a later tick tries again.

Structs

Waiter

The waiter’s state: the store it watches and what it must remember between ticks (only which inputs it has already failed on).

Enums

Action

What to do about one question, this tick.

Word

What the agent has not read yet.

Constants

TICK

How often the waiter looks at the store.

Functions

decide

The whole decision, with no I/O.

decide_owned

decide, told whether the daemon owns the answer’s action.

run

The waiter’s loop, until stop is asked for.